Merge pull request #444 from dbabokin/master

Fixing tabs and trainling white spaces
Merge pull request #445 from dbabokin/master

Adding information about compiler used to build ISPC to make output.  Also adds line endings cleanup.
Target class redesign: data moved to private. Also empty target-feature attribute is not added anymore (generic targets).
Fix for #431: memory leak due to multiple TargetMachine creation
DataLayout is changed to be managed from single place. v4-128-128 is added to generic DataLayout
Merge pull request #448 from dbabokin/target_class

Redesign of Target class with several fixes
Implemented 3 more intrinsics on double precision vectors
Merge pull request #450 from jbrodman/master

Added implementations of 3 intrinsics for double precision vectors
Issue
Checks the required compiler otherwise prints an error message and exits program
Merge pull request #451 from Vsevolod-Livinskij/master

Issue #436