Add new author 'B. Callander' with id 5042

The id 5041 is already used in the branch ar1_fix.
Add rule to ignore files marked as work in progress (_wip)
Fix author name misspelling: 'P. Eraser' -> 'P. Fraser'

I added 'P. Eraser' to the known aliases of this author.
Fix misspelling for author 'M. Lai' -> 'M. Lal'

I recorded the misspelling as an alias.
Add author 'A. Slingo' with id=5043
Replace 'Julia Slingo' with 'A. Slingo' in AR2 WGI Ch2