encodings: Added check for non-8bit encodings in src tree.

This commit sanitizes source files for unicode encodings which
cause failures in downstream flows (docgen, python2 module loading,
etc...).

    * Removed explicit encodings from src files
    * Replaced 2 byte character encodings with ascii encodies:
        ± -> +/-
        ° -> deg
        “ -> "
        etc...
    * Added ctest to check src tree files for non-8bit encodings

Signed-off-by: Noel Eck <noel.eck@intel.com>

tests/check_file_encoding.py

@@ -0,0 +1,54 @@
+#!/usr/bin/python
+
+import unittest
+import os
+import chardet
+
+target_exts = ['.h', '.hpp', '.hxx', '.txt']
+valid_encodings = ['ascii', 'utf-8']
+
+class EncodingTests(unittest.TestCase):
+    '''Non-ascii/utf-8 encodings can cause failures on downstream tools
+    such as documentation-generation and python2 module loading.  This
+    class helps find those files which could cause an encoding problem'''
+
+    def test_headers_ascii(self):
+        '''Assert/print list of:
+            file:linenumber offending line
+        for all lines of matching files which are not in valid_encodings'''
+        # Keep a map of files with alternate encodes to report
+        invalid_files = {}
+
+        # Recusively search cwd for files with target_exts
+        for root, dirs, files in os.walk(os.curdir):
+            # Work on full paths
+            for file in files:
+                file = os.path.join(root, file)
+
+                # Skip any files not ending with target_exts
+                if not any(file.lower().endswith(x) for x in target_exts):
+                    continue
+
+                # Check each with chardet
+                with open(file, 'r') as f:
+                    for ndx, line in enumerate(f):
+                        result = chardet.detect(line)
+                        if not result['encoding'] in valid_encodings:
+                            if not invalid_files.has_key(file):
+                                invalid_files[file] = []
+                            invalid_files[file].append([ndx,line])
+
+        # Sort the failures by filename
+        skeys = list(invalid_files.keys())
+        skeys.sort()
+        invalid_lines = ''
+        for fn in skeys:
+            for line in invalid_files[fn]:
+                invalid_lines += '%s:%d %s' % (fn, line[0], line[1])
+
+        self.assertEqual( len(invalid_files), 0,
+                "\nThe following modules have alternate encodings:\n" + \
+                invalid_lines)
+
+if __name__ == '__main__':
+    unittest.main()