Add gir submodule and automatic build script

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "gir"]
+	path = gir
+	url = https://github.com/gtk-rs/gir

generator.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+
+from os import listdir
+from os.path import isfile, join
+from subprocess import call
+import sys
+
+need_rebuild = False
+
+def update_workspace():
+    with open('Cargo.toml', 'r') as f:
+        old_lines = f.readlines()
+    lines = old_lines[:]
+    with open('Cargo.toml', 'w') as f:
+        lines.insert(len(lines) - 1, '"gir",')
+        f.write(''.join(lines))
+    success = True
+    try:
+        call(['bash', '-c', 'cd gir && cargo build --release'])
+    except:
+        success = False
+    with open('Cargo.toml', 'w') as f:
+        f.write(''.join(old_lines))
+    return success
+    
+
+if not isfile('./gir/src'):
+    need_rebuild = True
+    print('=> Initializing gir submodule...')
+    call(['bash', '-c', 'git submodule update --init'])
+    print('<= Done!')
+
+question = 'Do you want to update gir submodule? [y/N]'
+if sys.version_info[0] < 3:
+    line = raw_input(question)
+else:
+    line = input(question)
+line = line.strip()
+if line.lower() == 'n' or len(line) == 0:
+    need_rebuild = True
+    print('=> Updating gir submodule...')
+    call(['bash', '-c', 'cd gir && git reset --hard HEAD && git pull -f origin master'])
+    print('<= Done!')
+
+if need_rebuild is True or not os.path.isfile('./gir/target/release/gir'):
+    print('=> Building gir...')
+    if update_workspace() is True:
+        print('<= Done!')
+    else:
+        print('<= Failed...')
+        sys.exit(1)
+
+print('=> Regenerating crates...')
+for entry in [f for f in listdir('.') if isfile(join('.', f))]:
+    if entry.startswith('Gir_Gst') and entry.endswith('.toml'):
+        print('==> Regenerating "{}"...'.format(entry))
+        call(['./target/release/gir', '-c', entry])
+        print('<== Done!')
+print('<= Done!')
+print("Don't forget to check if everything has been correctly generated!")

gir

@@ -0,0 +1 @@
+Subproject commit 01137358493a9e19382045c84a141273f7e29b46