Reworked and updated time zone settings

Signed-off-by: Piotrek <pepe@attika.ath.cx>
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.

Signed-off-by: Piotrek <pepe@attika.ath.cx>
Don't replace the time zone abbreviation with GMT.

Signed-off-by: Piotrek <pepe@attika.ath.cx>
Comment out unnecessary pre-mappings.

Signed-off-by: Piotrek <pepe@attika.ath.cx>
Change the default DST settings in the web UI to uclibc's defaults, which are also the defaults for the US.

Signed-off-by: Piotrek <pepe@attika.ath.cx>
Add some new cities to the time zone list.

Signed-off-by: Piotrek <pepe@attika.ath.cx>
Change the name of some time zone list entries.

Signed-off-by: Piotrek <pepe@attika.ath.cx>