tex2lyx: support further TIPA characters

tex2lyx: support further TIPA characters

- support for \textdoublevertline, \textvertline, \textglobfall
- support \!o and \!b and \!d and \!g and \!G and \!j
- support  and \*k and \*r and \*t and \*w
- register the package "tipa" if \textipa is detected in an equation
- add a \textipa equation to the testfile

(I failed to implement support for the TIPA character "\t*{ }" and the command "\=*".)