Alternate quotes between double and single with nesting
Description
Provides two new commands: \nlq and \nrq for nesting left and
right quotes that properly change between double and single
quotes according to their nesting level. For example, the input
\nlq Foo \nlq bar\nrq\ bletch\nrq will be typeset as if it had
been entered as "Foo 'bar' bletch".