structure: don't overread input when searching for "

When searching for the string terminator don't read past the ending
0-byte when escaping characters.
Add unit test for various escaping cases.
common: update for bison version check patch

Fix configure check with bison development version.

https://bugzilla.gnome.org/show_bug.cgi?id=728946
basetransform: Fix caps equality check

Instead of checking if our outcaps are equivalent to the previous incaps, and
if that is the case not setting any caps on the pad... compare against our
previous outcaps because that's what we care about.

Fixes some cases where the outcaps became equivalent to the previous incaps,
but the previous outcaps were different and we were then sending buffers
downstream that were corresponding to the caps we forgot to set on the pad.
Resulting in crashes or image corruption.
multiqueue: percentage is an absolute value

multiqueue's queues stored percent value is the percentage from 0
to 100 (max-size-*) and should be compared with the requested limit
(high_percentage) set by the user and not with 100% to check if
buffering should stop. Otherwise we are only stopping buffering when the
queue gets completely full.
queue2: percentage is relative to high-percent

When comparing percentage values, compare with 0-100 scale as it
has already been made relative to 0-high_percent, otherwise we mark
the queue as not buffering and report a 50% to the user. This leads to
a buffering stall as the user assumes the queue is still buffering but
it thinks it isn't.

https://bugzilla.gnome.org/show_bug.cgi?id=736969
docs: add GST_GL_* environment variables to 'Running GStreamer' section
triggercontrolsource: Fix short description for the docs