Reworked and updated time zone settings
According to
http://pubs.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html,
the part describing the TZ environment variable, only colon is a valid
separator in offset.
Don't replace the time zone abbreviation with GMT.
Comment out unnecessary pre-mappings.
Change the default DST settings in the web UI to uclibc's defaults,
which are also the defaults for the US.
Add some new cities to the time zone list.
Change the name of some time zone list entries.
Merge branch 'new_timezone_settings'