exec task test

added a test to the exec task (grunt/exec.js) to check if the app/AppInspector/.sencha/ folder exists that is needed for the build
misc changes

#1 added an exec task (grunt/exec.js) test to check app/AppInspector/.sencha/ folder is present as it is needed for Sencha CMD build. - PLEASE RUN npm

#2 Re-added app/manifest.json placeholders (name & description).

#3 Added German manifest locales.
misc changes

1) added an exec task (grunt/exec.js) test to check 'app/AppInspector/.sencha/' folder is present as it is needed for Sencha CMD build. - PLEASE RUN 'npm update' AFTER PROJECT UPDATE

2) Re-added 'app/manifest.json' placeholders (name & description).

3) Added German manifest locales.
Merge branch 'master' of github.com:stoe/AppInspector

* 'master' of github.com:stoe/AppInspector:
Merge pull request #15 from stoe/master

misc changes (please see comment)