VPP Python language binding - plugin support

- Moved Python generator tool to tools directory
- Added build-vpp-api Makefile target
- Generator now only creates a Python representation of the .api
  the rest of the framework is in the vpp_papi script
- Each plugin has its own namespace.
- Plugin Python files are installed in vpp_papi_plugins for easy
  use inside the build tree.

Change-Id: I272c83bb7e5d5e416bdbd8a790a3cc35c5a04e38
Signed-off-by: Ole Troan <ot@cisco.com>
diff --git a/.gitignore b/.gitignore
index 4252618..8cbf1e6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,7 +13,6 @@
 /build-root/*.rpm
 /build-root/*.changes
 /build-config.mk
-/vpp-api/python/vpp_papi/vpp_papi.py
 /dpdk/*.tar.gz
 /dpdk/*.tar.xz
 /path_setup
@@ -51,7 +50,7 @@
 .settings
 # stop autotools ignore
 
-# OSX and some IDE 
+# OSX and some IDE
 .DS_Store
 .idea/
 .project
@@ -63,6 +62,7 @@
 GPATH
 GRTAGS
 GTAGS
+TAGS
 
 # Generated documentation
 /build-root/docs