.pytool/Plugin: Add CI plugins

https://bugzilla.tianocore.org/show_bug.cgi?id=2315

Add .pytool directory to the edk2 repository with the
following plugins.  These plugins are in a top level
directory because that can be used with all packages
and platforms.

* CharEncodingCheck
* CompilerPlugin
* DependencyCheck
* DscCompleteCheck
* GuidCheck
* LibraryClassCheck
* SpellCheck

Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

.pytool/Plugin/CharEncodingCheck/Readme.md

@@ -0,0 +1,18 @@
+# Character Encoding Check Plugin
+
+This CiBuildPlugin scans all the files in a package to make sure each file is
+correctly encoded and all characters can be read.  Improper encoding causes
+tools to fail in some situations especially in different locals.
+
+## Configuration
+
+The plugin can be configured to ignore certain files.
+
+``` yaml
+"CharEncodingCheck": {
+    "IgnoreFiles": []
+}
+```
+### IgnoreFiles
+
+OPTIONAL List of file to ignore.