smurf: Revert to a single noise value per bolometer for short obs

If the length of the time stream is less than two noise boxes, then
revert to using a single variance for each bolometer. Prior to this
change, makemap would fail in these circumstances saying that the "Size
of window exceeds extent of data array".
smurf: Limit each map dimension rather than total number of pixels

An error is now reported by makemap if either map dimension exceeds
20000. Previously, the error was only reported if the total number of
pixels in the map exceeded 20000*20000.
snurf: Remove nasty kludge used to avoid JSA tile issues at RA=12h

Disabling wrapping of RA values within the AST WcsMap class is no longer
needed since we now use the HPX12 projection in such cases.
Revert "ast: Add F77 interfaces for astGetWcsWrap and astSetWcsWrap"

This reverts commit eeefd91b2044fab70d3a7a94cfa22bd22065d915.

Disabling wrapping of longitude values by the WcsMap class is a bad idea.
It adds "special case" confusion, and should not really be necessary.
Revert "ast: Allow wrapping of lon/lat values to be disabled in WcsMap"

This reverts commit b8cfaafdf5ca877cb15a625b55897154be095a2a.

Disabling wrapping of longitude values by the WcsMap class is a bad idea.
It adds "special case" confusion, and should not really be necessary.