plugins: Move plugins to dedicated submodule

This change groups the plugin modules together under kas.plugins and
moves the @kasplugin decorator to this submodule. This will ensure the
codebase stays organised as more plugins are added.

Signed-off-by: Paul Barker <pbarker@konsulko.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kas/plugins/__init__.py

@@ -0,0 +1,35 @@
+# kas - setup tool for bitbake based projects
+#
+# Copyright (c) Siemens AG, 2017-2018
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+"""
+    This module contains and manages kas plugins
+"""
+
+
+def kasplugin(plugin_class):
+    """
+        A decorator that registers kas plugins
+    """
+    if not hasattr(kasplugin, 'plugins'):
+        setattr(kasplugin, 'plugins', {})
+    getattr(kasplugin, 'plugins').update({
+        plugin_class.name: plugin_class
+    })