pidgin/pidgin

Replace the manual browser opening code with gtk_show_uri_on_window

Remove the browser preference page.

replace the manual open uri code with gtk_show_uri_on_window

Testing Done:
Compiles, preference window functions properly, however talkatu doesn't handle links correctly so I couldn't test from messages or `help -> about`, but `help -> online help` worked just fine.

Reviewed at https://reviews.imfreedom.org/r/59/
ZEPHYRSOURCES = [
'ZAsyncLocate.c',
'ZCkAuth.c',
'ZCkIfNot.c',
'ZClosePort.c',
'ZCmpUID.c',
'ZCmpUIDP.c',
'ZFlsLocs.c',
'ZFlsSubs.c',
'ZFmtAuth.c',
'ZFmtList.c',
'ZFmtNotice.c',
'ZFmtRaw.c',
'ZFmtRawLst.c',
'ZFmtSmRaw.c',
'ZFreeNot.c',
'ZGetLocs.c',
'ZGetSender.c',
'ZGetSubs.c',
'ZGetWGPort.c',
'ZIfNotice.c',
'ZInit.c',
'ZLocations.c',
'ZMakeAscii.c',
'ZMkAuth.c',
'ZNewLocU.c',
'ZOpenPort.c',
'ZParseNot.c',
'ZPeekNot.c',
'ZPeekPkt.c',
'ZPending.c',
'ZReadAscii.c',
'ZRecvNot.c',
'ZRecvPkt.c',
'ZRetSubs.c',
'ZSendList.c',
'ZSendNot.c',
'ZSendPkt.c',
'ZSetDest.c',
'ZSetFD.c',
'ZSetSrv.c',
'ZSubs.c',
'ZVariables.c',
'ZWait4Not.c',
'ZhmStat.c',
'Zinternal.c',
'internal.h',
'mit-copyright.h',
'mit-sipb-copyright.h',
'sysdep.h',
'zephyr_err.h',
'zephyr_internal.h',
'zephyr.c',
'zephyr.h'
]
ZEPHYRSOURCESEXT = ['zephyr.c', 'zephyr.h']
extdep = krb4
if EXTERNAL_LIBZEPHYR
ZEPHYRSOURCES = ZEPHYRSOURCESEXT
extdep = ext_zephyr
endif
if DYNAMIC_ZEPHYR
zephyr_prpl = shared_library('zephyr', ZEPHYRSOURCES,
c_args : '-Dlint',
dependencies : [extdep, libpurple_dep, glib],
install : true, install_dir : PURPLE_PLUGINDIR)
endif