This also adds some other cleanups I performed on my way.

llvm-svn: 141275

Polly should now be compiled with CLooG 0c252c88946b27b7b61a1a8d8fd7f94d2461dbfd
and isl 56b7d238929980e62218525b4b3be121af386edf. The most convenient way to
update is utils/checkout_cloog.sh.

llvm-svn: 141251

The tool is called checkout_cloog.sh. We also update the get_started
documentation to include this tool. An older unfinished tool called
'get_cloog.sh' is removed to avoid confusion.

llvm-svn: 141212

llvm-svn: 139363

llvm-svn: 139362

llvm-svn: 134153

In some cases it is necessary to use a version of isl that is more recent than
the one included with CLooG. Point out what is needed to get such a version.

llvm-svn: 134152

llvm-svn: 132761

Use the content of the Polly wiki page[1] to create a new website. I do not yet
plan to officially promote this website, but it is already a solid base that we
can improve and peer review.

[1] http://wiki.llvm.org/Polly

llvm-svn: 130689