perf tools: Fix modifier to be applied on correct events

The event modifier needs to be applied only on the event definition it
is attached to.

The current state is that in case of multiple events definition (in
single '-e' option, separated by ',') all will get modifier of the last
one.

Fixing this by adding separated list for each event definition, so the
modifier is applied only to proper event(s). Added automated test to
catch this, plus some other modifier tests.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1332267341-26338-3-git-send-email-jolsa@redhat.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>