make pysnmp version available at MibBuilder

CHANGES.txt

@@ -2,6 +2,8 @@
 Revision 4.4.2, released 2017-11-XX
 -----------------------------------
 
+- The pysnmp version being used gets exposed to the MIB modules
+  via the `MibBuilder` instance
 - The .setObjects() method of the SMI types now accepts
   `append=False` parameter to let the caller adding more
   than 255 elements over the course of multiple calls

pysnmp/smi/builder.py

@@ -16,6 +16,7 @@
     from errno import ENOENT
 except ImportError:
     ENOENT = -1
+from pysnmp import __version__ as pysnmp_version
 from pysnmp.smi import error
 from pysnmp import debug
 
@@ -235,13 +236,18 @@ def _getData(self, f, mode):
 
 
 class MibBuilder(object):
-    loadTexts = 0
     defaultCoreMibs = os.pathsep.join(
         ('pysnmp.smi.mibs.instances', 'pysnmp.smi.mibs')
     )
     defaultMiscMibs = 'pysnmp_mibs'
+
     moduleID = 'PYSNMP_MODULE_ID'
 
+    loadTexts = False
+
+    # MIB modules can use this to select the features they can use
+    version = pysnmp_version
+
     def __init__(self):
         self.lastBuildId = self._autoName = 0
         sources = []