Fix minor typos in GSocketConnectable example code
Updated Telugu Translations
Clarify GValueArray docs

Don't refer to Quicksort in the documentation of
g_value_array_sort, but just to qsort().
Updated Odia Translation.
Remove a preprocessed-out code section

If it has not been needed since 2000, there probably is no use for it.
Moved the G_MAIN_POLL_DEBUG stuff to gmain-internal.h

Now that code is about to drift from gmain.c into the poll backend,
the debug infrastructure should better be shared in the header.
I'm too lazy to deduplicate it in gpoll.c, though.
Factored the poll backend out of GMainContext

Defined GMainContextFuncs, the backend vtable for
pluggable main loop implementations.
The new constructor g_main_context_new_custom() can be used
to create contexts with custom backends (and is used internally
for built-in backends).

This first backend, made largely from the existing code, is special
in another way: the methods of GMainContext that were designed around
GPollFunc will be only supported by the poll backend.
The context will switch to the poll backend to complete
any of these functions.
Added the epoll backend for GMainContext