Add Tree View

[ericfranz]

Fixes https://github.com/AweSim-OSC/osc-fileexplorer/issues/54

[ericfranz]

• [x] race condition means sometimes tree view is loaded first instead of after panel on initial load, resultin in a directory not being selected i..e I go to https://websvcs08.osc.edu/pun/dev/files/fs/nfs/17/efranz/Desktop/ but Desktop is not selected even though its visible to me (but other times it is)
• [x] Home Directory root node should be clickable to navigate back to root node
• [x] Create a directory in your home directory or in a directory that is visible in the tree - the tree needs to be updated
• [x] Delete a directory - the tree needs to be updated

Fix styles:

• [x] "root" node Home Directory always displays on top
• [x] scroll part fills on right side along panel
• [x] add border around
• [x] change the icons to be the same folder icons
• [x] change selection color so its the same
• [x] change background of tree panel so it is that grey #f5f5f5

[ericfranz]

@brianmcmichael please review - this appears to be working in IE10, Safari 8, Firefox, and Chrome.