Merge pull request #32 from gamerson/master

Added explicit check for ICompilationUnit. Fixes #31
improved code completion of attritubes in jsp file

jsp tokenizer doesn't detect the attribute value really well,
causes the code completion proposal to replace more text than it should
Merge pull request #33 from kuozhang/improved-code-completion-of-attritubes-in-jsp-file

improved code completion of attritubes in jsp file
Make sure that base content types are always searched