This reverts commit 6680d8b7.

It was added because the default RelWithDebInfo type disabled
assertions, but now that -DNDEBUG is removed from its flags, it is not
necessary to change the build type anymore.

failmalloc and main tests succesfully pass the test now.

Fix Windows build by defining `ssize_t` when missing and adjusting the
install commands.

Add support for ENABLE_WERROR=1 while at it.

Tested with MSVC 2013 on Windows 7 x64.

Avoid adding a LIBXML2_LIBRARIES-NOTFOUND to the libraries list when it
is not found. Likewise for OpenSSL.

Matches autotools behavior. The m4_if logic was misread...

Do not add _U_ and NGHTTP2_NORETURN definitions to the command line,
instead add it to config.h. This matches what autotools does.

Users can disable this by setting -DCMAKE_C_FLAGS=-DNDEBUG or
-DCMAKE_CXX_FLAGS=-DNDEBUG to disable assertions as desired.

src/Makefile.am: fix missing allocator.h

Build type-specific flags are added before other flags, reflect this in
the output.

NOTE: RelWithDebInfo *disables* assertions by default. To keep
assertions, use CMAKE_BUILD_TYPE=Debug or CMAKE_BUILD_TYPE=None.

Fix regression from v1.8.0-38-gbae37e3e breaking distcheck.

Add Nathan's PPA for cmake 3.2.3 (3.0 or newer is required).

Update to latest master with appropriate cmake changes at the same time.

Adds missing source files and configure.ac changes since
v1.7.0-93-g093eb51f.

Fixes and improvements for Makefile.MSVC