Replace build scripts with CMake

Rebuilding everything each time was getting a bit slow.

CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.10)
+
+project(regex-engine LANGUAGES C)
+
+option(SANITIZERS "Enable address and UB sanitizers")
+
+enable_testing()
+
+function(set_default_target_options target)
+  set_property(TARGET ${target} PROPERTY C_STANDARD 11)
+  target_compile_options(${target} PRIVATE -Wall -Wextra -pedantic)
+  if(${SANITIZERS})
+	target_compile_options(${target} PRIVATE -fsanitize=address,undefined)
+	target_link_options(${target} PRIVATE -fsanitize=address,undefined)
+  endif()
+endfunction()
+
+add_subdirectory(lib)
+add_subdirectory(tests)