Puts markers on top of marker clusters
uses another instructor symbol
new past_bootcamp pin. Marker symbols now same as cluster symbol on all levels
Adds marker clustering to maps of previous bootcamps
Adds spiderfying to map of previous bootcamps
Revert "new past_bootcamp pin. Marker symbols now same as cluster symbol on all levels"

This reverts commit 88de251e421d4b8ee5e5095842aacb257f608f59.
Revert "uses another instructor symbol"

This reverts commit 1a6a1d7caab6719d30b4b6424892a3a84d802b80.
Revert "Puts markers on top of marker clusters"

This reverts commit 75fd05d735a2bbfea20499d5e7f0597c550d1068.
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'here/master'
Merge pull request #177 from BernhardKonrad/master

Puts marker clusters behind bootcamp markers. Also: New bootcamp & instructor icons