Solving the multiple chart problem in the most straightforward way. Note that I could make it more resilient to more charts being added in show.html, but not worth it, given that the chart view will be entirely re-written to be on the front end later on anyways. @wilo99: please note that inserting more than one chart block into show.html is a bug at the moment.
PLD: use drop hover on new chart button
Merge pull request #569 from onaio/568_single_submission_view_chart

Solving the multiple chart problem in the most straightforward way. Note...