add a new build system

This commit adds a new build system based on waf. Configure is deprecated
effective immediately and someday in the future it will be removed. You can
find how the choice for waf came to be in the related rst file.
waf: kill mng support

was forgotten after a rebase
osxbundle: make the generation tool directory indipendent

This tool was assuming mpv was in the pwd and did not work if the binary name
was prefixed bit a subdirectory name.

Now it's possible to call the tool with the waf build directory:
`TOOLS/osxbundle.py --skip-deps build/mpv`
waf: fix --disable to also skip required dependencies
waf: fix debug flag being broken
waf: maybe fix pthreads check

I realized the generic check must also run on windows
waf: remove option for dummy-osd
waf: check misc options before everything else

Fixes static builds.
waf: fix glob() win32 replacement check
waf: merge miscellaneous options to build options

gives more clarity! :)
waf: reorganize imports a little
build: let old build system coexist with waf

Rename configure and the makefile, because otherwise it will severely
confuse users. Normally ./configure && make is the way to build, which
in our case would use the old build system.

./old-configure will actually create the Makefile, so "make" will still
work after ./old-configure is run.

Don't create config.h in the top-level directory, because the waf build
would pick it up and create a major confusing mess. Create it in
old_build/ instead, and add it as include path to the CFLAGS. config.mak
could stay in the root, but move it to old_build too for symmetry.
build: verify downloaded waf binary

I don't feel particularly good about executing automatically downloaded
files from the internet without verification. Verify the downloaded
executable with sha256sum, which is part of GNU coreutils, and should be
ubiquitous enough.

Now it should be impossible to run a downloaded file other than what the
hash stored in autogen.sh indicates, which in turn is bound to the git
commit hash.

If she256sum is not available, print a warning, and don't make waf
executable.
autogen.sh: print some instructions what to do next
waf: 32 bit x86 is "x86", not "x86_32"
autogen.sh: use shasum instead of sha256sum

Makes it work on hipster systems.
waf: fix pthreads check on win32 again

Python doesn't do implicit returns. Too much Ruby is bad for my health :)
waf: rename ./autogen.sh to ./bootstrap.sh

autogen.sh is generally used in autotools projects so it might confuse people
travis: use the new waf build system
waf: add support for bundle generation

this generates a non distributable version of the bundle