Add a check for toMathML before displaying TeX input tool
Change toMathML call to callback to avoid errors
Fix timing bug for toMathML check
Update shifted files
Test for tex2jax extension for TeX input
Use TeX Jax Config signal
Provide satistactory test for tex2jax and autoload toMathML if TeX present
Relocate MathJax check
Update version
Merge branch 'master' into MOODLE_25_STABLE