www: Add information about code coverage and static analysis

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@193466 91177308-0d34-0410-b5e6-96231b3b80d8
www: Add information about isl-0.12.1 release

Polly can now be compiled without explicitly linking to GMP licensed code.

This patch also contains some formatting improvements.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@193467 91177308-0d34-0410-b5e6-96231b3b80d8