pidgin/pidgin

Add the cpu, cpu_family, and endianness of the host machine to the about dialog

Also added the Adwaita version as that'll be handy too.

Testing Done:
Opend the about box and verified there weren't any warnings and that all of the data looked accurate.

Reviewed at https://reviews.imfreedom.org/r/2910/
if get_option('doc')
subdir('libpurple')
subdir('protocols')
if ENABLE_GTK
subdir('pidgin')
else
pidgin_doc = []
endif
if enable_consoleui
subdir('finch')
else
finch_doc = []
endif
alias_target('doc', libpurple_doc, protocols_doc, pidgin_doc, finch_doc)
endif