* Added `targets` API to all existing build rules
* Updated examples
* Restore making the make toolchain always available.
* Add support for generator cmake parsing and setting CMAKE_MAKE_PROGRAM
* Cleaned up duplicate generator arguments
* Fixed cmake tests
* Updated docs
* Addressed PR feedback
* Fixed missing and incorrect generators
* Fixed `generate_args` name
Fix #232 - enable usage of Bazel-built libraries as dependencies of cmake_external and configure_make.
- fix logic of reading library data described by C/C++ Bazel interface (as CcInfo.linking_context appeared)
- symlink transitive include directories under $EXT_BUILD_DEPS
- gather all possible transitive include directories to pass to CMake, pass transitive include directories to CMAKE_PREFIX_PATH so that the transitive include directories were scanned by CMake
- fix logic of passing transitive libraries into CPPFLAGS (configure_make)
- add test with the chain: Bazel lib -> CMake lib -> Bazel cc_test
- add synthetic configure-make test with the chain: Bazel lib -> configure_make lib -> Bazel cc_test
- also notice, that passed include directories from Bazel C/C++ Sandwich interface are not always existing; for now, make symlinking code resistant to that
see https://www.gnu.org/software/autoconf/manual/autoconf-2.63/html_node/Preset-Output-Variables.html
