Simplify build process by getting rid of bison/flex dependencies.

Fixes both MSVC and autotools (automake 1.12+).

Revert "Abort autogen.sh when automake 1.12+ is found."

This reverts commit 978ed8f1f90544162c327f334bd590cd7b944ce1.
Should now work with automake 1.11+

fixes ticket:3887
fixes ticket:3538
closes ticket:3950

(cherry picked from commit 372eff6693e633e8d0d1d0b8a9ceb996a5c3f49f)

Forgot to push these changes for commit 372eff6693e633e8d0d1d0b8a9ceb996a5c3f49f

(cherry picked from commit e397b24d4724d835d6cdc39a92800e64c0551dab)

Out of tree builds ?  Who needs them. :P

refs: 372eff6693e633e8d0d1d0b8a9ceb996a5c3f49f
(cherry picked from commit 20317c2a6f2c700042a727c6d719056ab3c90dcb)