Moving logme Require JS module out of individual XModules/Capa problems.

Avoids code duplication. The following files

    common/lib/xmodule/xmodule/js/src/poll/logme.js
    common/lib/xmodule/xmodule/js/src/word_cloud/logme.js
    common/lib/xmodule/xmodule/js/src/graphical_slider_tool/logme.js
    common/static/js/capa/drag_and_drop/logme.js

all defined the same module `logme`. At the current moment, there is no point for it. All of the `logme()` calls can be replaced with `console.log()` calls. Initially, the ideas was to move it to a separate file (avoiding code duplication, making it available for all other components). But in the course of discussing this PR with the reviewers, it was decided to remove `logme` altogether, and use `console.log` instead.

**Reviewers**

- @wedaly 
- @jmclaus 

**BLD-608**