Add optional CMake build script.

CMakeLists.txt

+# CMake build script for the libgit2 project
+# Theres nothing wrong with the original Waf build besides dependency on Python which I lack on some systems.
+# Peter Drahos 2010
+PROJECT(libgit2 C)
+CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+
+# Sane defaults
+OPTION (BUILD_SHARED_LIBS "Build Shared Library (OFF for Static)" ON)
+OPTION (BUILD_TESTS "Build Tests" ON)
+IF (NOT CMAKE_BUILD_TYPE)
+    SET(CMAKE_BUILD_TYPE "Release" CACHE STRING "Choose the type of build, options are: Debug Release RelWithDebInfo MinSizeRel." FORCE)
+ENDIF ()
+
+# Find dependencies
+FIND_PACKAGE(zlib REQUIRED)
+FIND_PACKAGE(OpenSSL REQUIRED)
+
+INCLUDE_DIRECTORIES(${ZLIB_INCLUDE_DIR} ${OPENSSL_INCLUDE_DIR} src)
+
+# Collect sourcefiles
+FILE(GLOB SRC src/*.c)
+FILE(GLOB SRC_GIT src/git/*.c)
+FILE(GLOB SRC_SHA src/block-sha1/*.c)
+FILE(GLOB SRC_PLAT src/unix/*.c)
+FILE(GLOB SRC_H src/git/*.h)
+
+# On Windows use specific platform sources
+IF (WIN32)
+    ADD_DEFINITIONS(WIN32 _DEBUG _LIB ZLIB_WINAPI)
+    FILE(GLOB SRC_PLAT src/win32/*.c)
+ENDIF ()
+
+# TODO. PPC Detection for optimized sha1.
+
+# Compile and link libgit2
+ADD_LIBRARY(git2 ${SRC} ${SRC_GIT} ${SRC_SHA} ${SRC_PLAT})
+TARGET_LINK_LIBRARIES(git2 ${ZLIB_LIBRARY} ${OPENSSL_CRYPTO_LIBRARIES})
+
+# Install
+INSTALL(TARGETS git2 
+    RUNTIME DESTINATION bin
+    LIBRARY DESTINATION lib
+    ARCHIVE DESTINATION lib
+)
+INSTALL(FILES ${SRC_H} DESTINATION include/git)
+
+# Tests
+IF (BUILD_TESTS)
+    # TODO. The Waf build generates *.toc files for each test which complicates things.
+ENDIF ()