.gitignore: Update

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
typedefs.h: Use upstream guards

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
CMakeLists: Use BUILD_SHARED_LIBS to specify the type of libraries to build

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
CMakeLists: Simplify config.h generation

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
CMakeLists: Only use the CFLAGS on GCC-like systems

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
CMakeLists: Group statements and add comments

Signed-off-by: Timothy Gu <timothygu99@gmail.com>