Rollup of minor fixes found by Martin Ettl
Use $(AR) instead of explicitly calling 'ar'

This simplifies overriding the command used, e.g. for cross
compilation.
Don't check for scene changes on forced IDR frames

For the first encoded frame, is bEncCurFrmAsIdrFlag true
while bIdrPeriodFlag is false.

Previously, the scene detection code unnecessarily checked for
a scene change in the first encoded frame (where the reference
frame was an uninitialized frame), triggering valgrind warnings
about using uninitialized memory.
Turn on -Werror for OSX builds
Merge pull request #66 from mstorsjo/valgrind

Don't check for scene changes on forced IDR frames
Replace some fancy stuff with simple function
memset not required as struct is already initialized to 0.

Moreover, memset causes loss of sDecParam.sVideoProperty.size
that was set previously.
Fix typo which ignored dec options file in dec testapp

Options file was not being taken because it was wrongly being taken as output
file for decoder.
Improve command line arguments handling in dec testapp

Problems fixed:
1. No longer segfaults if an option is specified without an accompanying argument.

2. Wrongly incrementing i by 3 instead of by 2 while parsing command line options.
Updated readme and CmdLineExamples to point to new make system.
Fix typo in CmdLineExamples.sh
typo correction
typo correction-- update another file
Merge pull request #73 from ruil2/master

typo correction
Merge pull request #70 from ethanhugg/readme

Updated readme and CmdLineExamples to point to new make system.
Merge pull request #58 from ethanhugg/othercontribs

Rollup of minor fixes found by Martin Ettl
Merge pull request #69 from ethanhugg/cosmetic

Turn on -Werror for OSX builds
Add MinGW platform makefile and related source changes
Remove extra [:digit:] from tr command
Add workaround for missing strnlen.

Enabled by default, define HAVE_STRNLEN to disable workaround.