[svn ci] svn metadata cleanup

[Jerry Gay]

for those of you who might be updating your working copies from svn
(post r10933) and wondering why so many files are changing, i did some
svn metadata cleanup today.

~ the set svn:mime-type property should now be set appropriately based
on file extension. i paid close attention to .t, .xml, .png (and other
image formats), .z3. i may have missed some filetypes, but they should
have the same properties they had before, which may already have been
correct.
~ the svn:keywords property should now be standardized to "Author Date
Id Revision" for all text files.
~ removed mistaken svn:keyword properties from files that had this
typo-ed property.

i've tested on i386-win32-cl and i386-linux-gcc successfully. if you
notice anything unusual, please report any bugs to the usual place
(parr...@parrotcode.org.)
~jerry