store corrected lat long for knots

[DanOvando]

eastings are flipped when flip_around_dateline is TRUE, resulting loc_x containing "incorrect" eastings and UTM zones. While this is accounted for by later functions, direct plotting of supplied eastings and UTM zone will place data in the wrong location on a map (e.g. eastings in knot panel of Data_and_knots.png are not correct for the lat/lon coordinates in the extrapolation panels when flip_around_dateline == T). Functionconvert_utm_to_lltakes supplied UTM coordinates and zones and converts them back to lat-long coordinates, reversing the "flip_around_dateline" if required, so that a corrected lat-long for knot locations is available to users. Corrected values are stored as a separate data.frame by Spatial_Information_Fn.R
Function has been checked for regions that do and do not flip around dateline, and ran VAST--single-species_example.Rmd with updated SpatialDeltaGLMM package to verify that it still works.

[DanOvando]

Joys of Ubuntu.... spatial dependencies can be installed through

sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable
sudo apt-get update
sudo apt-get install libgdal-dev libgeos-dev libproj-dev libudunits2-dev liblwgeom-dev