Initial bits to process initializers in variable declarations

Initial bits to process initializers in variable declarations

As a result, the following tests pass:

    glslparsertest/array3.frag
    glslparsertest/CGStandardLibrary.frag
    glslparsertest/ConstantConversions.frag
    glslparsertest/constructor1.frag
    glslparsertest/constructor2.frag
    glslparsertest/constructor3.V110.frag
    glslparsertest/dataType4.frag
    glslparsertest/dataType5.frag
    glslparsertest/dataType13.frag
    glslparsertest/dataType19.frag
    glslparsertest/matrix.V110.frag
    glslparsertest/parser7.frag
    glslparsertest/swizzle3.frag

The following tests also pass, but it is just by dumb luck.  In these
cases the shader fails to compile, but it fails for the wrong reason:

    glslparsertest/array6.frag
    glslparsertest/comma2.frag
    glslparsertest/conditional1.frag
    glslparsertest/conditional2.frag
    glslparsertest/conditional3.frag
    glslparsertest/constFunc.frag
    glslparsertest/ParseTest3.frag
    glslparsertest/ParseTest4.frag
    glslparsertest/varying3.frag
    glslparsertest/parser8.frag (also segfaults)
    glslparsertest/parser9.frag (also segfaults)

The following tests now fail.  As far as I can tell, these are all
cases where the shader was failing to compile, but it was failing for
the wrong reason.

    glslparsertest/CorrectMatComma.frag
    glslparsertest/CorrectModule.frag
    glslparsertest/CorrectSwizzle2.vert
    glslparsertest/shaders/glsl-fs-bug25902.frag