* Revert "Removed CMakeLists.txt. (Fix#421)"
This reverts commit 8674555b88.
* Fail if cmake version too old
Previous behaviour is just a warning.
* Improve CMakeLists
Adds automatic dependency finding (if they were used).
Adds a way to require a specific version in the find_package(httplib) call.
You should link against the httplib::httplib IMPORTED target, which is
created automatically.
Add options to allow for strictly requiring OpenSSL/ZLIB
HTTPLIB_REQUIRE_OPENSSL & HTTPLIB_REQUIRE_ZLIB require the libs be found, or the build fails.
HTTPLIB_USE_OPENSSL_IF_AVAILABLE & HTTPLIB_USE_ZLIB_IF_AVAILABLE silently search for the libs.
If they aren't found, the build still continues, but shuts off support for those features.
* Add documentation to CMakeLists.txt
Has info on all the available options and what targets are produced.
Also put some things about installation on certain platforms.
