Add a script to compute information about sequences

This script print:
<input_video>, <nbFrames>, <width>x<height>
Add files with sequences we want to test
Copy the original mpeg4_tests, for retro-compatibility
(sequences_tests) Remove the old sequences list
(sequences_tests) New function to build command line
(sequences_tests) Clean command line options
(sequences_tests) Update content of the script
(sequences_tests) Allow passing more options to the command line
(sequences_tests) Remove useless sys.exit calls
(sequences_test) Refactoring !!
(sequences_test) Do not parse commented lines in fileList
(sequences_test) Allow filtering sequences to decode
(sequences_test) Catch external signals
(sequences_test) Do not crash if NB FRAMES not provided in inputList
(sequences_test) Fix input/yuv path issues
(sequences_test) Finalize command line interface
(sequences_test) Additional arguments add is more flexible
Merge branch 'modernize_scripts'