Bump version

Overview of changes:

 *  build target will now leave file .mkit/semver file

    Build tools can read this to easily find out version.

 *  semver() caches its output now

 *  Refactored common operations in .mkit

 *  Removed old unnecessary check

 *  Solved or muted last few ShellCheck issues

mkit.ini

 #mkit version=0.0.14
 
 [project]
-    version     = 0.0.24
+    version     = 0.0.25
     codename    = wilderness
     name        = MKit
     tagline     = Simple install helper