Service manager performance optimized

[Ocramius]

This PR inlines some of the methods internal to the service manager. Following changes may be potential BC breaks:

• canCreate has been deprecated (as it seems, it is an internal method anyway. Users should keep using has)
• isSubclassOf has been deprecated (was used internally)
• The canonical names map is re-used directly, instead of calling canonicalizeName each time

NOTE: if this one is ok, remove the performance test case before merging (or tell me to do so)

[Ocramius]

No idea whatsoever why the build fails. Ok, @weierophinney found out it's an un-related problem with RandomLib going out of memory.

For comparison, here's the results over 100000 iterations:

• Zend\ServiceManager\ServiceManager::get (with defined service):
  • before: 0.65002608299255
  • after: 0.2622389793396
• Zend\ServiceManager\ServiceManager::has (with defined service):
  • before: 0.65546894073486
  • after: 0.33996605873108
• Zend\ServiceManager\ServiceManager::has (without defined service):
  • before: 0.84106206893921
  • after: 0.517333984375
• Zend\ServiceManager\ServiceManager::create (without defined invokable):
  • before: 0.79828000068665
  • after: 0.70576095581055

[mwillbanks]

I see that also var_dump'd in the test... you may consider removing it :)

   [concat]                 ZendTest/ServiceManager
   [concat] 
   [concat]             PHPUnit 3.7.19 by Sebastian Bergmann.
   [concat] 
   [concat] Configuration read from /home/travis/build/zendframework/zf2/tests/phpunit.xml.dist
   [concat] 
   [concat] ........SS.string(73) "ZendTest\ServiceManager\ServiceManagerPerformanceTest::testGetPerformance"
   [concat] array(2) {
   [concat]   ["time"]=>
   [concat]   float(0.83468294143677)
   [concat]   ["iterations"]=>
   [concat]   int(100000)
   [concat] }
   [concat] .string(73) "ZendTest\ServiceManager\ServiceManagerPerformanceTest::testHasPerformance"
   [concat] array(2) {
   [concat]   ["time"]=>
   [concat]   float(1.0163159370422)
   [concat]   ["iterations"]=>
   [concat]   int(100000)
   [concat] }
   [concat] .string(86) "ZendTest\ServiceManager\ServiceManagerPerformanceTest::testHasPerformanceWithNoService"
   [concat] array(2) {
   [concat]   ["time"]=>
   [concat]   float(1.4539151191711)
   [concat]   ["iterations"]=>
   [concat]   int(100000)
   [concat] }
   [concat] .string(76) "ZendTest\ServiceManager\ServiceManagerPerformanceTest::testCreatePerformance"
   [concat] array(2) {
   [concat]   ["time"]=>
   [concat]   float(1.9051969051361)
   [concat]   ["iterations"]=>
   [concat]   int(100000)
   [concat] }
   [concat] ................................................... 65 / 74 ( 87%)
   [concat] .........
   [concat] 
   [concat] Time: 5 seconds, Memory: 11.25Mb
   [concat] 
   [concat] OK, but incomplete or skipped tests!
   [concat] Tests: 74, Assertions: 107, Skipped: 2.

[Ocramius]

@mwillbanks yes, these performance tests are here for the only purpose of showing that it works. I noted that in the PR description