shared: Introduce new top-level dir and move 1st party lib code there.

This commit moves all first-party code developed for this project from lib/
to shared/, so that lib/ now only contains third-party code.

The following directories are moved as-is from lib to shared:

    lib/libc            -> shared/libc
    lib/memzip          -> shared/memzip
    lib/netutils        -> shared/netutils
    lib/timeutils       -> shared/timeutils
    lib/upytesthelper   -> shared/upytesthelper

All files in lib/embed/ have been moved to shared/libc/.

lib/mp-readline has been moved to shared/readline.

lib/utils has been moved to shared/runtime, with the exception of
lib/utils/printf.c which has been moved to shared/libc/printf.c.

Signed-off-by: Damien George <damien@micropython.org>

shared/memzip/make-memzip.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python
+#
+# Takes a directory of files and zips them up (as uncompressed files).
+# This then gets converted into a C data structure which can be read
+# like a filesystem at runtime.
+#
+# This is somewhat like frozen modules in python, but allows arbitrary files
+# to be used.
+
+from __future__ import print_function
+
+import argparse
+import os
+import subprocess
+import sys
+import types
+
+def create_zip(zip_filename, zip_dir):
+    abs_zip_filename = os.path.abspath(zip_filename)
+    save_cwd = os.getcwd()
+    os.chdir(zip_dir)
+    if os.path.exists(abs_zip_filename):
+        os.remove(abs_zip_filename)
+    subprocess.check_call(['zip', '-0', '-r', '-D', abs_zip_filename, '.'])
+    os.chdir(save_cwd)
+
+def create_c_from_file(c_filename, zip_filename):
+    with open(zip_filename, 'rb') as zip_file:
+        with open(c_filename, 'wb') as c_file:
+            print('#include <stdint.h>', file=c_file)
+            print('', file=c_file)
+            print('const uint8_t memzip_data[] = {', file=c_file)
+            while True:
+                buf = zip_file.read(16)
+                if not buf:
+                    break
+                print('   ', end='', file=c_file)
+                for byte in buf:
+                    if type(byte) is types.StringType:
+                        print(' 0x{:02x},'.format(ord(byte)), end='', file=c_file)
+                    else:
+                        print(' 0x{:02x},'.format(byte), end='', file=c_file)
+                print('', file=c_file)
+            print('};', file=c_file)
+
+def main():
+    parser = argparse.ArgumentParser(
+        prog='make-memzip.py',
+        usage='%(prog)s [options] [command]',
+        description='Generates a C source memzip file.'
+    )
+    parser.add_argument(
+        '-z', '--zip-file',
+        dest='zip_filename',
+        help='Specifies the name of the created zip file.',
+        default='memzip_files.zip'
+    )
+    parser.add_argument(
+        '-c', '--c-file',
+        dest='c_filename',
+        help='Specifies the name of the created C source file.',
+        default='memzip_files.c'
+    )
+    parser.add_argument(
+        dest='source_dir',
+        default='memzip_files'
+    )
+    args = parser.parse_args(sys.argv[1:])
+
+    print('args.zip_filename =', args.zip_filename)
+    print('args.c_filename =', args.c_filename)
+    print('args.source_dir =', args.source_dir)
+
+    create_zip(args.zip_filename, args.source_dir)
+    create_c_from_file(args.c_filename, args.zip_filename)
+
+if __name__ == "__main__":
+    main()
+