meta: replace cmake mono-build system with a custom build co-ordinator

every system component now has its own self-contained build system, and a
seed file describing the component and its build system and dependencies.

a new tool, meadow, collects and uses these seed files to build the
components into a full system. meadow also manages the target system root
and a host prefix where toolchain tools are installed to.

the build system has also been updated to use a new $ARCH-rosetta-gcc
compiler, and the patches files necessary to build it have been
added to toolchain/cross-compiler.

toolchain/meadow/publish.py

@@ -0,0 +1,21 @@
+import os
+
+
+class Publish:
+    def __init__(self, **kwargs):
+        self.__data = None
+        self.__install_root = None
+
+        if 'data' in kwargs:
+            self.__data = kwargs['data']
+
+        if 'install_path' in kwargs:
+            self.__install_root = kwargs['install_path']
+
+
+    def path(self):
+        return self.__data.get('path', None)
+
+
+    def cmake(self):
+        return self.__data.get('cmake', None)