perf tools: Improve strfilter to append additional rules

Add strfilter__or/and to append additional rules to existing strfilter.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150424094744.23967.97614.stgit@localhost.localdomain


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