Fixed `_pauseTime` not being defined

thanks to the new lint task ! They are tons of other reported issues,
but global variables are always bad :)
Fixed a regression in the isometric renderer

following changes in the following commit :
https://github.com/melonjs/melonJS/commit/dd6af60165ee42fd58883250a671c5ceae5908d9
Merge remote-tracking branch 'origin/master' into matrix-based-transform