Update to the most recent mathjax node version

Change-Id: I49fec24bf9c21c531bb65f9f53d041e1b4c0293b
Fix: Load texvc macros from the TeX folder

The texvc extension file is located in the
TeX folder and not in the main extension folder

Change-Id: I7aae95c17462fd8675430f500199bef9cccd50ee