fate: remove last incomplete frame from mpeg2-field-enc test
configure: Fix silly typo in logging command of check_struct()
configure: Add sanitize_var_name convenience function

This is useful in all the places where special characters in
variable names are manually translated to underscores.
configure: Add check_builtin convenience function
configure: Use check_builtin() where appropriate
Merge commit '813b82b927b19532e3bc3397b972c8a27b9f6326'

* commit '813b82b927b19532e3bc3397b972c8a27b9f6326':
  configure: Fix silly typo in logging command of check_struct()
  fate: remove last incomplete frame from mpeg2-field-enc test

Conflicts:
	tests/fate/video.mak
	tests/ref/fate/mpeg2-field-enc

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'f868b24d0f280bb966e5c352028a343e45d20a02'

* commit 'f868b24d0f280bb966e5c352028a343e45d20a02':
  configure: Add sanitize_var_name convenience function

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '9c7d85b3b45a77742b1e69c48ab33f9c8a2e6f35'

* commit '9c7d85b3b45a77742b1e69c48ab33f9c8a2e6f35':
  configure: Add check_builtin convenience function

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  configure: Use check_builtin() where appropriate

Conflicts:
	configure

Merged-by: Michael Niedermayer <michaelni@gmx.at>
fate: add dependency for xface

Signed-off-by: Paul B Mahol <onemda@gmail.com>
mp3dec: Fix VBR bit rate parsing

When parsing the Xing/Info tag, don't set the bit rate if it's an Info tag.

When parsing the stream, don't override the bit rate if it's already set,
otherwise calculate the mean bit rate from parsed frames. This way, the bit
rate will be set correctly both for CBR and VBR streams.

Signed-off-by: Alexander Kojevnikov <alexander@kojevnikov.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>