Formatting changes and loading message added to dl estimator
Fixed travis errors
Changes made as per review

Loading spinner added
icons and associated formatting improved
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# On branch dl_estimate_speed_fixes
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	modified:   src/test/javascript/portal/cart/DownloadEstimatorSpec.js
#	modified:   src/test/javascript/portal/cart/DownloadPanelItemTemplateSpec.js
#	modified:   web-app/js/portal/cart/DownloadEstimator.js
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	web-app/js/GeoExt1.1/resources/images/default/anchor_new.png
#	web-app/js/GeoExt1.1/resources/images/default/anchor_top_new.png
#	web-app/js/portal/cart/.vagrant/
#	web-app/js/portal/cart/Vagrantfile
Merge pull request #904 from aodn/dl_estimate_load_msg

Formatting changes and loading message added to dl estimator