[gardening] Use consistent capitalization for "Python".

.gitignore

@@ -13,7 +13,7 @@
 *~
 # Merge files created by git.
 *.orig
-# Byte compiled python modules.
+# Byte compiled Python modules.
 *.pyc
 # vim swap files
 .*.sw[a-z]

docs/DebuggingTheCompiler.rst

@@ -217,7 +217,7 @@ we know to ignore swift_getGenericMetadata 84 times, i.e.::
 LLDB Scripts
 ````````````
 
-LLDB has powerful capabilities of scripting in python among other languages. An
+LLDB has powerful capabilities of scripting in Python among other languages. An
 often overlooked, but very useful technique is the -s command to lldb. This
 essentially acts as a pseudo-stdin of commands that lldb will read commands
 from. Each time lldb hits a stopping point (i.e. a breakpoint or a

tools/SourceKit/bindings/python/sourcekitd/capi.py

@@ -527,7 +527,7 @@ def register_function(lib, item, ignore_errors):
     try:
         func = getattr(lib, item[0])
     except AttributeError as e:
-        msg = str(e) + ". Please ensure that your python bindings are "\
+        msg = str(e) + ". Please ensure that your Python bindings are "\
                        "compatible with your sourcekitd version."
         if ignore_errors:
             return