Corrected "Usage" information in idngram2lm.
Added percentage counts to n-gram hits chart in evallm.
Improved the documentation slightly.
No longer refer to back-off weights as "alphas" in idngram2lm. So command line options like "-two_byte_alphas" and "-max_alpha" become "-two_byte_bo_weights" and "-max_bo_weight". The old forms are still supported, in order to provide consistency with V2.00.
Tools now terminate in the event of unrecognised command-line arguments (previously they simply displayed a warning).
Fixed bug in endian.sh.