Create an interactive porting tool

`blueprint-compiler port` interactively ports a project to blueprint.
It will create the subproject wrap file, add it to .gitignore, decompile
your GtkBuilder XML files, emit code to copy and paste into your
meson.build file, and update POTFILES.in.

It can't quite handle all of the features the forward compiler can, so
it will skip those files.

blueprintcompiler/utils.py

@@ -20,6 +20,18 @@
 import typing as T
 
 
+class Colors:
+    RED = '\033[91m'
+    GREEN = '\033[92m'
+    YELLOW = '\033[33m'
+    FAINT = '\033[2m'
+    BOLD = '\033[1m'
+    BLUE = '\033[34m'
+    UNDERLINE = '\033[4m'
+    NO_UNDERLINE = '\033[24m'
+    CLEAR = '\033[0m'
+
+
 def lazy_prop(func):
     key = "_lazy_prop_" + func.__name__