remove dependency on some unneeded qt packages

replace dependecy on whole qt toolkit with required packages only
pulseview: decoders respect USE flag
Fix name of enable flag for sigrokdecode
Merge pull request #5 from pinkavaj/fix-qt-deps-01

remove dependency on some unneeded qt packages
Merge pull request #6 from zeldin/master

Fix name of enable flag for sigrokdecode
remove redundant pulseview DECODE flag that got added when I haphazardly merged
libsigrokdecode: use python-single-r1

This _should_ cause us to select the correct python3 config, but right
now also needs a use flag.

Fixes #8 (kind of)
new versions
readme update
helpful hints.
repoman fix
manifest...
sigrok-cli needs newer libsigrokdecode
deps, and configuration
sigrok has a funny idea about --with
fixup
fixup
fixup
ah, it is broken...
libsigrokdecode fixups