add request tags support
add request tags to pinba_get_info()
add pinba_request_time_set()
add hostname to pinba_get_info() result
Merge branch 'request_tags'

* request_tags:
  add hostname to pinba_get_info() result
  add pinba_request_time_set()
  add request tags to pinba_get_info()
  add request tags support
allow changing pinba.server with ini_set()