sdist and install now work

next step is using a custom data dir, and falling back on the package
data dir. Also, fixing --version.

overviewer_core/optimizeimages.py

@@ -0,0 +1,49 @@
+#    This file is part of the Minecraft Overviewer.
+#
+#    Minecraft Overviewer is free software: you can redistribute it and/or
+#    modify it under the terms of the GNU General Public License as published
+#    by the Free Software Foundation, either version 3 of the License, or (at
+#    your option) any later version.
+#
+#    Minecraft Overviewer is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+#    Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License along
+#    with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import subprocess
+import shlex
+
+pngcrush = "pngcrush"
+optipng = "optipng"
+advdef = "advdef"
+
+def check_programs(level):
+    path = os.environ.get("PATH").split(os.pathsep)
+
+    for prog,l in [(pngcrush,1), (optipng,2), (advdef,2)]:
+        if l <= level:
+            result = filter(lambda x: os.path.exists(os.path.join(x, prog)), path)
+            if len(result) == 0:
+                raise Exception("Optimization prog %s for level %d not found!" % (prog, l))
+
+def optimize_image(imgpath, imgformat, optimizeimg):
+    if imgformat == 'png':
+        if optimizeimg >= 1:
+            # we can't do an atomic replace here because windows is terrible
+            # so instead, we make temp files, delete the old ones, and rename
+            # the temp files. go windows!
+            subprocess.Popen([pngcrush, imgpath, imgpath + ".tmp"],
+                stderr=subprocess.STDOUT, stdout=subprocess.PIPE).communicate()[0]
+            os.remove(imgpath)
+            os.rename(imgpath+".tmp", imgpath)
+
+        if optimizeimg >= 2:
+            subprocess.Popen([optipng, imgpath], stderr=subprocess.STDOUT,
+                stdout=subprocess.PIPE).communicate()[0]
+            subprocess.Popen([advdef, "-z4",imgpath], stderr=subprocess.STDOUT,
+                stdout=subprocess.PIPE).communicate()[0]
+