FileMock: allow append content
Merge pull request #142 from milo/pull-filemock-append

FileMock: allow append content
Option --stop-on-error renamed to --stop-on-fail
Merge pull request #143 from milo/pull-rename-stoparg

Option --stop-on-error renamed to --stop-on-fail
Assert::contains prevents E_WARNING when $needle is ''
Check $_SERVER[argv] existency [Closes #145]

E.g. it is not set when test run from browser.
Runner: added TEST_FILE_EXTENSION
Runner: accept [ and ] in directory path
create-phar: standalone PHAR can be used as Tester and as testing bootstrap
Dumper::dumpException() ignores in stack trace class Assert
Dumper::dumpException() prints function arguments
Dumper::dumpException() prints line of source code whether Assert is called