trydiff: remove unused variable 'modifiedset' We started updating 'modifiedset' in a9853fc172d2 (trydiff: simplify checking for additions, 2014-12-23) but in the same commit, we removed the last use of the variable. Clean it up.

revset: replace parsing alias definition by _parsealiasdefn to parse strictly Before this patch, referring alias arguments is parsed by string base operation "str.replace". This causes problems below (see the previous patch introducing "_parsealiasdefn" for detail) - the shorter name argument breaks referring the longer name - argument names in the quoted string are broken This patch replaces parsing alias definition by "_parsealiasdefn" to parse strictly.