Merge branch 'build_cmake' of https://github.com/TcT2k/wxWidgets

Add CMake-based build system.

Merge the original branch without any changes except for resolving the
conflict due to moving the contents of .travis.yml to a separate file by
propagating the changes done in this file since then to the new script
and rerunning ./build/update-setup-h and ./build/cmake/update_files.py
to update the file lists changed in the meanwhile.

Closes https://github.com/wxWidgets/wxWidgets/pull/330

build/cmake/update_files.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python
+
+#############################################################################
+# Name:        build/cmake/update_files.py
+# Purpose:     Convert build/files to files.cmake
+# Author:      Tobias Taschner
+# Created:     2016-09-20
+# Copyright:   (c) 2016 wxWidgets development team
+# Licence:     wxWindows licence
+#############################################################################
+
+import os
+import re
+
+outpath = os.path.dirname(os.path.abspath(__file__))
+
+infile = open(outpath + "/../files", "r")
+outfile = open(outpath + "/files.cmake", "w")
+outfile.write("# Automatically generated from build/files by " + os.path.basename(__file__) + "\n")
+outfile.write("# DO NOT MODIFY MANUALLY !\n\n")
+
+# Compile regular expressions
+var_ex = re.compile('([\w]+)[\s]*=')
+comment_ex = re.compile('^[#]+')
+evar_ex = re.compile('\$\(([\w]+)\)')
+cmd_ex = re.compile('^<')
+
+files = None
+var_name = None
+
+def write_file_list():
+    # Write current list of files to output file
+    if not var_name:
+        return
+
+    outfile.write('set(' + var_name + '\n')
+    for file in files:
+        outfile.write('    ')
+        vm = evar_ex.match(file)
+        if vm:
+            # Convert variable reference to cmake variable reference
+            outfile.write('${'+vm.group(1)+'}')
+        else:
+            outfile.write(file)
+        outfile.write('\n')
+
+    outfile.write(')\n\n')
+
+for line in infile.readlines():
+    # Ignore comment lines
+    m = comment_ex.match(line)
+    if m:
+        continue
+    m = cmd_ex.match(line.strip())
+    if m:
+        # Ignore bake file commands but note them in the target file in
+        # case we might need them
+        line = '#TODO: ' + line
+
+    # Check for variable declaration
+    m = var_ex.match(line)
+    if m:
+        write_file_list()
+
+        var_name = m.group(1)
+        files = []
+    else:
+        # Collect every file entry
+        file = line.strip()
+        if file and var_name:
+            files.append(file)
+
+# Write last variable
+write_file_list()
+
+infile.close()
+outfile.close()