The time module has the inverse function of localtime() in its mktime
() function, but is missing the inverse of gmtime().

After a bit of searching, I found the calendar module function timegm
(), which claims to be the inverse of gmtime().

Is there any reason the time module shouldn't provide the inverse of 
gmtime()?  It's obviously needed, as the calendar module has a 
version for its own use since the time module doesn't provide one.

See patch #1667546 for an implementation of timegm.