softscope: reset display when pipe is reopened, change data format to
    float, make pipe name a command line parameter, change default pipe
    name to softscope.fifo

original bzr status:
revno: 50
committer: Norbert Braun <braun@groofy>
branch nick: xrp-1
timestamp: Sat 2010-10-09 17:00:42 +0200
add .gitignore
Softscope: changes Qt::DotLine to Qt::DashLine, because MacOS doesn't support DotLine
softscope: fix include guards