- cleaned up all the compiler warnings

- cleaned up all the compiler warnings
- for getopt.c, this involved moving the line:
      extern char *getenv(const char *name);
  outside of the two nested #ifdefs that it was inside, as it is always required (the code that calls it isn't inside any #ifdefs) Perhaps this may break compilation in non-linux/gnu environments?

git-svn-id: http://svn.osgeo.org/postgis/trunk@202 b70326c6-7e19-0410-871a-916f4a2858ee