Normalize line endings

This partially addresses Issue #2955. I added a .gitattributes file which tells git to automatically recognize text files and normalize the line endings. It also ensures that .pde files and .java files are always treated as text.  All of the previously un-normalized files are now normalized.  You may be able to merge these file without all of the explicit changes by using the merge.renormalize option.  I am not entirely certain on that though and how it works.