Ensures consistent latitude/longitude header

Makes sure longitude is always "Longitude" and latitude is always
"Latitude" when input.
Bugfixes / Polygons for 1 point
Grid Updating Functions / 2 point polygon change

Grid Updating Functions - For numeric data interpolates between min and
max values that can be calculated using InitTileMinMax() - results
stored in m_minFieldValue and m_maxFieldValue, but not saved.
2 point polygon change - polygons with only 2 points are smoother.
solved merge conflicts with Justin
Fixing a few merge issues
renamed and updated all polygon files
Fixed polygon error after changing to pointers
Showspread restore tree/right-click hide locations

Hiding locations now updates trees too
Updating for showAll/hideAll locations
LocationSet Show All and Hide All locations
Tree manipulation additions

Collapse/expand subtree, zoom in/ zoom out of subtree, split tree, and
restore tree
added OAuth libraries to Python
minor changes to plugins
Original tree is retained on tree split

Also removed colour ordering number (added in tree manipulation
additions) because it's unnecessary.
Bugfixes

The geographic axis visibility is now copied and the tree can be split
with a resulting tree being a single root node.
Merging
Changes for Mac compatability
local fiddling with ShowSpread and Gridding
Revert "local fiddling with ShowSpread and Gridding"

This reverts commit 11d56599182f21489b39ea6ef2314ad7e4f9ef5f.
fixed bug in Gridding with ShowSpread