Added CLIENT SET/GETNAME command
Added PHPUnit utility method markTestSkippedOnRedisVersionBelow and applied it where necessary
[tests] Fix version check to work on Redis < 2.6.0.

INFO does not have the concept of sections prior to 2.6.0 while our
test suite can be run against 2.4.0 (provided that phpunit.xml uses
the correct server profile), so we need to make sure that the check
does not break with prior version of Redis even if this is unlikely
to happen at this point.

Also changed a bit the naming of variables since things are already
pretty much explicit in this context.
Merge branch 'gh/pr/102' into v0.8