Support full POSIX-style time zone: EST+3, PST-3, etc.

We probably support a superset of the spec, but I don't have the spec
 to confirm this.
Update regression tests to include tests for this format.
Update geometry.out with results from Linux RH 5.2 system
(for last decimal place).

Author: Thomas G. Lockhart

src/test/regress/expected/geometry.out

@@ -150,11 +150,11 @@ SELECT '' as six, box(f1) AS box FROM CIRCLE_TBL;
  six |                                    box                                     
 -----+----------------------------------------------------------------------------
      | (2.12132034355964,2.12132034355964),(-2.12132034355964,-2.12132034355964)
-     | (71.7106781186548,72.7106781186548),(-69.7106781186548,-68.7106781186548)
-     | (4.53553390593274,6.53553390593274),(-2.53553390593274,-0.535533905932738)
+     | (71.7106781186547,72.7106781186547),(-69.7106781186547,-68.7106781186547)
+     | (4.53553390593274,6.53553390593274),(-2.53553390593274,-0.535533905932737)
      | (3.12132034355964,4.12132034355964),(-1.12132034355964,-0.121320343559642)
      | (107.071067811865,207.071067811865),(92.9289321881345,192.928932188135)
-     | (170.710678118655,70.7106781186548),(29.2893218813452,-70.7106781186548)
+     | (170.710678118655,70.7106781186547),(29.2893218813453,-70.7106781186547)
 (6 rows)
 
 -- translation
@@ -502,31 +502,31 @@ SELECT '' AS twentyfour, c1.f1 AS circle, p1.f1 AS point, (p1.f1 <-> c1.f1) AS d
    FROM CIRCLE_TBL c1, POINT_TBL p1
    WHERE (p1.f1 <-> c1.f1) > 0
    ORDER BY distance, circle, point using <<;
- twentyfour |     circle     |   point    |     distance      
-------------+----------------+------------+-------------------
-            | <(100,0),100>  | (5.1,34.5) | 0.976531926977965
-            | <(1,2),3>      | (-3,4)     |  1.47213595499958
-            | <(0,0),3>      | (-3,4)     |                 2
-            | <(100,0),100>  | (-3,4)     |  3.07764064044151
-            | <(100,0),100>  | (-5,-12)   |  5.68348972285122
-            | <(1,3),5>      | (-10,0)    |  6.40175425099138
-            | <(1,3),5>      | (10,10)    |  6.40175425099138
-            | <(0,0),3>      | (-10,0)    |                 7
-            | <(1,2),3>      | (-10,0)    |  8.18033988749895
-            | <(1,2),3>      | (10,10)    |   9.0415945787923
-            | <(0,0),3>      | (-5,-12)   |                10
-            | <(100,0),100>  | (-10,0)    |                10
-            | <(0,0),3>      | (10,10)    |   11.142135623731
-            | <(1,3),5>      | (-5,-12)   |  11.1554944214035
-            | <(1,2),3>      | (-5,-12)   |  12.2315462117278
-            | <(1,3),5>      | (5.1,34.5) |  26.7657047773223
-            | <(1,2),3>      | (5.1,34.5) |   29.757594539282
-            | <(0,0),3>      | (5.1,34.5) |  31.8749193547455
-            | <(100,200),10> | (5.1,34.5) |  180.778038568384
-            | <(100,200),10> | (10,10)    |  200.237960416286
-            | <(100,200),10> | (-3,4)     |  211.415898254845
-            | <(100,200),10> | (0,0)      |  213.606797749979
-            | <(100,200),10> | (-10,0)    |  218.254244210267
-            | <(100,200),10> | (-5,-12)   |  226.577682802077
+ twentyfour |     circle     |   point    |     distance     
+------------+----------------+------------+------------------
+            | <(100,0),100>  | (5.1,34.5) | 0.97653192697797
+            | <(1,2),3>      | (-3,4)     | 1.47213595499958
+            | <(0,0),3>      | (-3,4)     |                2
+            | <(100,0),100>  | (-3,4)     | 3.07764064044152
+            | <(100,0),100>  | (-5,-12)   | 5.68348972285122
+            | <(1,3),5>      | (-10,0)    | 6.40175425099138
+            | <(1,3),5>      | (10,10)    | 6.40175425099138
+            | <(0,0),3>      | (-10,0)    |                7
+            | <(1,2),3>      | (-10,0)    | 8.18033988749895
+            | <(1,2),3>      | (10,10)    |  9.0415945787923
+            | <(0,0),3>      | (-5,-12)   |               10
+            | <(100,0),100>  | (-10,0)    |               10
+            | <(0,0),3>      | (10,10)    |  11.142135623731
+            | <(1,3),5>      | (-5,-12)   | 11.1554944214035
+            | <(1,2),3>      | (-5,-12)   | 12.2315462117278
+            | <(1,3),5>      | (5.1,34.5) | 26.7657047773223
+            | <(1,2),3>      | (5.1,34.5) |  29.757594539282
+            | <(0,0),3>      | (5.1,34.5) | 31.8749193547455
+            | <(100,200),10> | (5.1,34.5) | 180.778038568384
+            | <(100,200),10> | (10,10)    | 200.237960416286
+            | <(100,200),10> | (-3,4)     | 211.415898254845
+            | <(100,200),10> | (0,0)      | 213.606797749979
+            | <(100,200),10> | (-10,0)    | 218.254244210267
+            | <(100,200),10> | (-5,-12)   | 226.577682802077
 (24 rows)