Changed Data to Survey as per Issue #61
updates to survey and mkvc
Updates to linear problem
Issue #62: real coords for plotSlice.
fixed plotGrid 1D error
Clean up plot image code. Now shared between plotSlice and plotImage
Minor updates to Linear Problem.
Merge branch 'master' of https://github.com/simpeg/simpeg into cylClean

Conflicts:
	SimPEG/Mesh/View.py