Merge pull request #511 from Eric89GXL/vol-fix

FIX: is_surface() for volume source spaces
ENH+FIX: Read extra meas info, fix raw concat error
FIX: Minor test fix
ENH: Allowing overwriting of raw files
ENH: Adding viz.compare_fiff()
STY: Cleaner
typo
fix manifest
FIX: Allow bads exclusion at proj stage
STY: Better description
STY: Typo
FIX: Adding test
FIX: Several testing fixes
Merge pull request #514 from Eric89GXL/make_proj_fx

FIX: Allow bads exclusion at proj stage, testing warnings
ENH: Adding subject parameter to SourceEstimate and Label^C
ENH: More consistent use
FIX: Minor fix
FIX: Better comment
FIX: Minor fixes
FIX: Several fixes