Fix all warnings:  Linux, Windows-64, Windows-32

Minimum changes to fix all warnings for linux, windows builds.

I have specially reviewed these five modules, where I have added typecasts of (int) --
* src/plugins/perl.c
* src/common/dcc.c
* src/common/hexchat.c
* src/common/plugin-timer.c
* src/common/text.c

and they all seem for one reason or another to be the most reasonable fix.  As to how to format a time_t compatibly for 32- and 64-bit systems, for example, http://stackoverflow.com/questions/11748247/size-of-time-t-and-its-max-value shows it to be ambiguous (src/common/hexchat.c).
Still shouldn't cast ```time_t``` to ```int```...