file permissions for HILIS4 fastcgi process:
.aspell.$ctr.temp 644 www-data:staff (temporary file for new words pending merge with .pws)
.aspell.$ctr.pws  644 www-data:staff (personal dictionary)
.aspell.en.prepl  644 www-data:staff (stores replacement pairs when you tell aspell to learn from mistakes - not used)
en-medical.rws    644 root:root (just needs to be readable)

# to create master/extra-dict (needs to be done in situ - 32bit & 64bit not cross-compatible):
# in static/speller/dicts
aspell --lang=en create master ./en-medical.rws < ./src/en-medical-sorted.txt
