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/path.py

@@ -0,0 +1,88 @@
+import glob
+import os
+
+
+class Path:
+    def __init__(self, value):
+        self.__path = value
+        self.__namespace = None
+
+        parts = value.split(':')
+
+        if len(parts) != 2:
+            return
+
+        if len(parts[0]) < 3:
+            return
+
+        self.__namespace = parts[0]
+        self.__path = parts[1]
+
+
+    def get_path(self):
+        return self.__path
+
+
+    def remove_root(self):
+        while len(self.__path) > 0 and self.__path[0] == '/':
+            self.__path = self.__path [1:]
+
+        if len(self.__path) == 0:
+            self.__path= '.'
+
+        return self
+
+
+    def expand_path(self, **kwargs):
+        relative_to = None
+
+        if 'relative_to' in kwargs:
+            relative_to = kwargs['relative_to']
+
+            if isinstance(relative_to, dict):
+                if self.__namespace is not None:
+                    relative_to = relative_to[self.__namespace]
+                else:
+                    relative_to = None
+
+        paths = glob.glob(self.__path, root_dir=relative_to, recursive=True)
+        if len(paths) == 0 and '*' not in self.__path:
+            if relative_to is not None:
+                return [os.path.join(relative_to, self.__path)]
+            return [self.__path]
+
+        if relative_to is not None:
+            abs_paths = []
+
+            for p in paths:
+                abs_paths.append(os.path.join(relative_to, p))
+
+            return abs_paths
+
+        return paths
+
+
+    def expand_all(paths, **kwargs):
+        relative_to = None
+
+        if 'relative_to' in kwargs:
+            relative_to = kwargs['relative_to']
+
+        result = []
+        for p in paths:
+            if not isinstance(p, Path):
+                p = Path(p)
+            r = p.expand_path(relative_to=relative_to)
+            result.extend(r)
+
+        return result
+
+
+    def get_namespace(self, **kwargs):
+        if self.__namespace is not None:
+            return self.__namespace
+
+        if 'default' in kwargs:
+            return kwargs['default']
+
+        return None