lavfi: add avfilter_init_dict() for initializing a filter with a dict.
lavfi: mark filters with dynamic number of inputs or outputs with special flags

This will be useful in avtools in the following commits.
Any other caller might also want to know this information.
lavfi: add a function for counting elements in AVFilterPad arrays.

The caller needs to know what valid indices can be passed to
avfilter_pad_get_name/type.
lavfi: change the filter registering system to match the other libraries

Removes an arbitrary hardcoded limit on the number of filters.
lavfi: do not segfault on NULL passed to avfilter_get_by_name()
avconv: update to the new options syntax.

The separators were changed from ',' to '|' in all the filters.
avconv: print filter options in -h full output.
Merge commit '1ba95a9cca57b023b9b9de071a5671fc05b05e58'

* commit '1ba95a9cca57b023b9b9de071a5671fc05b05e58':
  lavfi: add avfilter_init_dict() for initializing a filter with a dict.

Conflicts:
	libavfilter/avfilter.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '7cdd737ba81b5c2c9521c4509edf0ac315fabc65'

* commit '7cdd737ba81b5c2c9521c4509edf0ac315fabc65':
  lavfi: mark filters with dynamic number of inputs or outputs with special flags

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '7e8fe4be5fb4c98aa3c6a4ed3cec999f4e3cc3aa'

* commit '7e8fe4be5fb4c98aa3c6a4ed3cec999f4e3cc3aa':
  lavfi: add a function for counting elements in AVFilterPad arrays.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'fa2a34cd40d124161c748bb0f430dc63c94dd0da'

* commit 'fa2a34cd40d124161c748bb0f430dc63c94dd0da':
  lavfi: change the filter registering system to match the other libraries

Conflicts:
	cmdutils.c
	ffplay.c
	libavfilter/avfilter.c
	libavfilter/avfilter.h

This removes the ability to put AVFilters in read only memory and having
them shareable.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'f160c6a18a574b4c7d063e0a748037cbbd9912ee'

* commit 'f160c6a18a574b4c7d063e0a748037cbbd9912ee':
  lavfi: do not segfault on NULL passed to avfilter_get_by_name()

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'bee2d75b66e2f02e0877796c01202299a4b56cfb'

* commit 'bee2d75b66e2f02e0877796c01202299a4b56cfb':
  avconv: update to the new options syntax.

Conflicts:
	ffmpeg_filter.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'dc574658d15ad8f171dbdecbdce7197acf9424a0'

* commit 'dc574658d15ad8f171dbdecbdce7197acf9424a0':
  avconv: print filter options in -h full output.

Conflicts:
	ffmpeg_opt.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avfilter: Filter options that are used for both video and audio should have both flags

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
asetpts: add AVOptions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter: add missing AV_OPT_FLAG_FILTERING_PARAM

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>