Update BUILD.txt with correct Xcode spelling

Also update this file by replacing all XCode instances with Xcode.
Merge pull request #185 from mcclure/mingw

MinGW support updates
Merge pull request #142 from mcclure/xmlbreak

TinyXML fixes: linebreaks, license junk
Made NEWLINE default to unix newline in tinyxml
Merge pull request #181 from chrisledet/patch-2

Update BUILD.txt with correct Xcode spelling
Merge pull request #153 from mcclure/cslisten

Give some way to recover from CoreInput::removeAllHandlers()
Improved notion of Bullet 'found': don't assume absent debug libraries mean absent Bullet, and if Bullet is *really* absent, then don't try to build the binaries.