Revert "fix bug; layouts/layout.tex.erb should be used if exists"
Revert "fix bug; layouts/layout.tex.erb should be used if exists"

This reverts commit b8e189ecebcdc78a17687f0f5f34ab4354a406e7.

krororo/review,orangain/review,kmuto/review,takahashim/review,krororo/review,krororo/review,kmuto/review,takahashim/review,kmuto/review,orangain/review