Fixed error checking for environmental search, added all values option to environmental search

Error checking for all input fields in environmental search, now accepts negative numbers and decimals

[ ] all checkbox to environmental search ( #86 ) - gets all EnvironmentalValues for a specified variable, finds the min and max values and sets these to environmentalData.vals[0] and environmentalData.vals[1], respectively.

Still need to do:
Not sure where to position the checkbox.