calculations for interval and time/timetz to behave sanely for both
integer and float timestamps; up to now I think it's been doing
something pretty strange...
- Fix wrong index results on text, char, varchar for multibyte strings
- Fix some SIGFPE signals
- Add support for infinite timestamps
- Because of locale settings, btree_gist can not be a prefix index anymore (for text).
Each node holds now just the lower and upper boundary.