cmake support in rippled. Currently supports:
* unity/nounity debug/release
* running protobuf
* sanitizer builds
* optional release build with assert turned on
* `target` variable to easily set compiler/debug/unity
(i.e. -Dtarget=gcc.debug.nounity)
* gcc/clang/visual studio/xcode
* linux/mac/win
* gcc 4 ABI, when needed
* ninja builds
* check openssl for acceptably recent release
* static builds
TBD:
* jemalloc support
* count
Notes:
* Use the -G"Visual Studio 14 2015 Win64" generator on Windows. Without
this a 32-bit project will be created. There is no way to set the
generator or force a 64-bit build in CMakeLists.txt (setting
CMAKE_GENERATOR_PLATFORM won't work). The best solution may be to
wrap cmake with a script.
* It is not possible to generate a visual studio project on linux or
mac. The visual studio generator is only available on windows.
* The visual studio project can be _either_ unity or
non-unity (selected at generation time). It does not appear possible
to disable compilation based on configuration.
* Language is _much_ worse than python, poor documentation and "quirky"
language support (for example, generator expressions can only be used
in limited contexts and seem to work differently based on
context (set_property can set multiple values, add_compile_options
can not/or is buggy)
* Could not call out to `sed` because cmake messed with the regular
expression before calling the external command. I did not see a way
around this.
* Makefile generators want to be single target. It wants a separate
directory for each target type. I saw some mentions on the web for
ways around this bug haven't look into it. The visual studio project
does support debug/release configurations in the same project (but
not unity/non-unity).
