Enable NTS to handle SV tiles.

[schlafly]

• optional increased verbosity when scheduler cannot schedule a tile
• only prepend FASURV to FAFLAVOR when FAFLAVOR does not already include the survey
• default to 0 HA in planning when no pre-planned LST is available
• add tileprogram to tiles object
• add routines to compute number of unique nights a tile was observed on in dark/gray/bright conditions, needed for SV completeness
• let LST optimization work for mixed programs making use of DARK/GRAY/BRIGHT time
• let LST optimization work when tiles need time in multiple kinds of conditions
• add feature to LST optimization removing tiles that have already been observed
• let tiles in LST optimization have different exposure lengths
• handle exptime = 0 correctly in LST optimization
• minor cleanups

[weaverba137]

Is there a reason the branch nts-in-sv has not been deleted?