pdf-js.c: Use different random number.

0.4 is not exactly representable using floats, and libjs uses a different
atod function than v8.
pdf-util.js: Simplify padZeros.
Add MuJS submodule, implementation and build.

Adds simpler choice of Javascript library to makefiles.
Will prefer in order: MuJS, JavaScriptCore, V8, none based
on HAVE_MUJS, HAVE_JSCORE, and HAVE_V8.

For simplicity, we build mujstest even with no javascript implementation.
Break dependency of pdf-annot.c to graphics library.
Break dependencies on pdf-form.c and pdf-js.c

Split functions out of pdf-form.c that shouldn't be there, and make
javascript initialization explicit.
Split mjs script generation to separate tool.

It has no real reason to live in mudraw, and it does pull in the
javascript dependency via pdf-form.c.
Update win32 project files for JS.
Use MuJS in Android build.
Fix typo in Makefile.
Update the winrt solution with the changes made in the win32 solution.

Also update the code for the changes made in the stream API