Get version string for docs from CMakeLists.txt

Because it's better to have a single source.
Someone else will need to integrate the makefiles though.

conf.py

@@ -13,6 +13,7 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
+import fnmatch
 import sys
 import os
 import shlex
@@ -54,11 +55,22 @@ author = 'The DFHack Team'
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
-#
+
+def get_version():
+    """Return the DFHack version string, from CMakeLists.txt"""
+    version, release = '', ''
+    with open('CMakeLists.txt') as f:
+        for s in f.readlines():
+            if fnmatch.fnmatch(s.upper(), 'SET(DF_VERSION "?.??.??")\n'):
+                version = s.upper().replace('SET(DF_VERSION "', '')
+            elif fnmatch.fnmatch(s.upper(), 'SET(DFHACK_RELEASE "r*")\n'):
+                release = s.upper().replace('SET(DFHACK_RELEASE "', '').lower()
+    return (version + '-' + release).replace('")\n', '')
+
 # The short X.Y version.
-version = '0.40.24-r3'
+version = get_version()
 # The full version, including alpha/beta/rc tags.
-release = '0.40.24-r3'
+release = get_version()
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -75,7 +87,7 @@ language = None
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ['docs/_build']
+exclude_patterns = ['docs/_build/*', 'depends/*']
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.