#38 Compilation fixes for Cinelerra4 source

[Anonymous]

I noticed while attempting to compile Cinelerra4 on openSUSE x86_64 that several #includes seem to be missing. I was able to fix compilation by adding the following #includes to the following files:
thirdparty/mjpegtools-1.9.0rc3/mpeg2enc/encodertypes.h
<limits.h>
<stdlib.h>

thirdparty/mjpegtools-1.9.0rc3/mplex/inputstrm.cpp
<limits.h>

thirdparty/mjpegtools-1.9.0rc3/mplex/multiplexor.cpp
<string.h>

thirdparty/mjpegtools-1.9.0rc3/mplex/padstrm.cpp
<string.h>

thirdparty/mjpegtools-1.9.0rc3/mplex/main.cpp
<string.h>

thirdparty/openexr-1.6.1/exrmaketiled/main.cpp
<string.h>

thirdparty/openexr-1.6.1/exrenvmap/main.cpp
<string.h>

I checked mjpegtools' project on sourceforge, and 1.9.0 does include these headers, though openexr-1.6.1 from sourceforge does not.