Starting menu api

Committing my progress on the menu api before I go to bed. Will finish as soon as I get a chance.
Create stringUtils

Came up with an idea to fix another problem and put it here in a new API. This API can be expanded on in future, it could be a good place to put all sorts of handy string manipulation functions.
Rename src/stringUtils to src/apis/stringUtils
Rename src/apis/stringUtils to src/api/stringUtils
Merge pull request #4 from trajing/casilleroDev

Casillero dev