Import v3.31
Import v3.33
Import v3.34
Import v3.35
Merge tag 'v3.31'
Merge tag 'v3.33'
Merge tag 'v3.34'

Conflicts:
	configure
	configure.in

Had to reapply a bit of a1081e96d9e2d1265df644ae8b5d62ed0cb396ce
Ignore cache directory
Merge tag 'v3.35'

v3.35 CFITSIO

Conflicts:
	configure
	configure.in

Had to add CFLAGS to reimplement a1081e96d9e2d1265df644ae8b5d62ed0cb396ce

Regenerated configure using autoconf.