SCUBA2: always re-read header after storing noise results

Previously the pirmitive only re-read the header if the number of
files stored was >1. However, that statement assumed the case of n=1
corresponded to there only being 1 input file, and not that 3 of 4
subarrays had failed to produce results.

Since re-reading the header for a single file carries little overhead,
it seems worth re-reading the header in all cases so avoid potential
downstream "files_from_hdr" errors,
(cherry picked from commit aef7d0366101c213b0b5dfa7332c05cd68c52e20)
SCUBA2: unset FLATFIELD flag if set once a map stored

The FLATFIELD uhdr flag is used in a couple of places to determine
whether to perform further analysis. Once a map has been made
successfully and stored in the current Frame, this flag should be
unset to indicate that the Frame no longer contains flatfielded data.
(cherry picked from commit f1beb14292a3f815c05427f2dec306be79638e76)
SCUBA2: calculate zenith NEFD for map-based calculations

For some reason, the zenith NEFD was calculated for noise observations
but not for map-based NEFD calculations.
(cherry picked from commit 1f83a031b7ec646662cf5aa1fe981a570c971747)
SCUBA2: remove debug print statement
(cherry picked from commit a348ac7163f453e526960e13a181a8f854f5642a)
SCUBA2: recipe parameters and config for default JPS processing
(cherry picked from commit b940b02219ea8c7057bc6628668080ba8fdc8bfe)
SCUBA2: use correct module for tau conversion

Repeat after me: use JCMT::Tau::SCUBA2 for SCUBA2 tau conversions...
(cherry picked from commit 060f7d55c4693fd3967e03a8dac65293a5b7fb05)