Added the lake object

Added the lake object that currently prints its rainfall, PET and water
amounts before rain and evaporation each tick.
Added the river object and began to testing
Updated with upstream and fixed conflicts
Added the Manning roughness cofactor to the river
Merged with upstream, broken
Merge branch 'master' of https://github.com/paivola/mapserver
More problems, still broken
Just another commit
Re-wrote some of the code for better quality
Commenting, tweaking variables and testing with data
Ready to merge with the rest
merged water