Pedantic C compilation and version macros

* Adds compiler flags to enable pedantic compilation,
  use the C99 standard, use position independent code for
  64-bit architectures, and enable all warning levels.
* Specifies the watchdog library version numbers as C
  preprocessor macros passed to the C source code.
* Adds `libm` as a library to link against. This should
  have been default for gcc.

Signed-off-by: Gora Khargosh <gora.khargosh@gmail.com>

setup.py

@@ -56,15 +56,31 @@
 else:
     platform = None
 
+_watchdog_fsevents_sources = [
+    os.path.join(SRC_DIR, '_watchdog_fsevents.c'),
+    os.path.join(SRC_DIR, '_watchdog_util.c'),
+]
+
 ext_modules = {
     PLATFORM_MACOSX: [
         Extension(name='_watchdog_fsevents',
-                  sources=[os.path.join(SRC_DIR,
-                                        '_watchdog_fsevents.c'),
-                           os.path.join(SRC_DIR,
-                                        '_watchdog_util.c')],
+                  sources=_watchdog_fsevents_sources,
+                  libraries=['m'],
+                  define_macros=[
+                      ('WATCHDOG_VERSION_STRING', version.VERSION_STRING),
+                      ('WATCHDOG_VERSION_MAJOR', version.VERSION_MAJOR),
+                      ('WATCHDOG_VERSION_MINOR', version.VERSION_MINOR),
+                      ('WATCHDOG_VERSION_BUILD', version.VERSION_BUILD),
+                  ],
                   extra_link_args=['-framework', 'CoreFoundation',
-                                   '-framework', 'CoreServices']
+                                   '-framework', 'CoreServices'],
+                  extra_compile_args=[
+                      '-std=c99',
+                      '-pedantic',
+                      '-Wall',
+                      '-Wextra',
+                      '-fPIC',
+                      ]
                   ),
     ],
 }