Verify build on Windows 7/VS 2010.  Change to Apache license.  Specifically:

    -- Added WIN32 settings to Makefiles.
    -- SeExpression.cpp: Dereference vector rbegin() instead of end() to fix runtime error in prep().
    -- SeExprEdGrapher2d.cpp: Use float args in call to pow() to fix compile error
    -- SeExprSpecParser.y: Fix undefined snprintf
    -- SeExprSpecParserLex.l: Fix undefined math symbols
    -- imageSynth.cpp: Use vector to replace const array of dynamic size
Fixes FXSOFT-142: [SeExpr] Example expressions path is hard-coded

set IMAGE_EDITOR_ROOT as define to use for adding examples to browser
INSTALL *.se examples into install root subdir
new public method: addUserExpressionPath
Address comments from pull request #11, verifying windows build.
Updated imageEditor UI tutorial docs for example expressions path
Merge branch 'jberlin-editor' into editor (resolve pull request)