Finish T::S::R::D side of #103

This squashes the following commits:

7401bfb added more tests for find_no_element_ok, so had to fix things a bit
3bbdcec Factorised the setting of test level in the role
3395e2e rewrote how find_no_element_ok works
2515922 Rewrote the T::S::R::D class : added a role common to the two testing classes so that code gets factorised
c699015 Moved the unless clause so it is more efficient
8d7627d replaced  with __PACKAGE__ when installing the subs, more foolproof
852c64c Fixed a redefine bug as the subs get reinstalled every time an object get instanciated
9d5cbd8 Refactoring of T::S::R::WebElement, less code, more magic

Conflicts:
	lib/Selenium/Remote/Driver.pm
	lib/Test/Selenium/Remote/Driver.pm
	lib/Test/Selenium/Remote/WebElement.pm
	t/Test-Selenium-Remote-Driver.t
Update generated cpanfile with new deps from #103
Satisfy [PkgVersion] with newline and bump version for trial
Update Changes

[skip ci]
Merge pull request #122 from gempesaw/finish-moo-merge-103

Finish moo transition; resolves #103 and fixes #121.