Implemented (somewhat kludgily) option for phonetics scheme to
replace e with é iff it is the last letter of the last tsheg bar.
This is required by the new THDL phonetics spec.
New algorithm, per new THDL phonetics spec, for ba->wa processing.
The heuristic is that it applies only to the last tsheg bar in
multi-tsheg-bar words. (Previously, ba always generated "?ba/wa?",
which is maybe more correct but less attractive.) This heuristic
fails on, e.g., "tsheg bar". Oh well.
Rationalized format of phonetics file: > is used as separator in exceptions
as well as rules. (Previously, : was used in exceptions only.)