vsh: Introduce vshInitReload

vsh: Introduce vshInitReload

Commit a0b6a36f separated vshInitDebug from the original vshInit
(before virsh got split and vshInit became virshInit - commit 834c5720)
in order to be able to debug command line parsing.
After the parsing is finished, debugging is reinitialized to work properly.
There might as well be other features that require re-initialization as
the command line could specify parameters that override our defaults which
had been set prior to calling vshArgvParse.