Remove obsolete line from AnalyzedPHPFileTest
Simplify PHPShortTagsTest
Move redundant boilerplate from tests to a common parent class

This includes all tests except for AnalyzedPHPFileTest, BaseScannerTest,
and VIPInitCheckTest, which are a bit more complex. Also, JavaScriptLintTest
and VIPParametersTest could use some more optimization, possibly requiring
some extra parameters or logic in CheckTestBase::runCheck().
Fix malformed PHP in the AnalyzedPHPFileTest

These occurrences cannot be really parsed by the PHP interpreter,
which would break the test if a more compliant PHP parser was used.
Merge pull request #196 from ockham/tests-boilerplate

Move redundant boilerplate from tests to a common parent class
Merge pull request #201 from ockham/fix-malformed-tests

Fix malformed PHP in the AnalyzedPHPFileTest
Remove duplicated display() class method from RendererGroup, fixing bugs

This is actually achieved by replacing the version in RenderGroup's parent
class AnalyzerRenderer (which was buggier, missing one esc_attr() and an
"\n" in bare mode) with the one from RendererGroup, and replacing one
is_null() check for the contents of a member variable by an isset() (which
extends the check to the existence of that member).
Merge pull request #208 from ockham/remove-duplicate-display-class-method

Remove duplicated display() class method from RendererGroup
Add unit tests for the register_widget() check.
Use a parenthesis when checking for the register_widget() function.

This matches the earlier check for register_sidebar(), but a regex match
might be more robust. It prevents a false positive for functions that
use the 'register_widget' slug in their name, for instance,
'prefix_register_widget_areas'.
Update the WidgetsTest class to extend the new CheckTestBase class.
Include additional boilerplate in the unit test for register_widget() to be sure the error being tested isn't related to other widget issues.
Update the unit test checking for register_widget in function names to include additional variations.
Use regex to reduce false positives in the check for register_widget().
Include required  arg in preg_match_all() for compatibility with PHP 5.3.