Merge pull request #1 from pbesedm/feature/pluginmanager

Feature/pluginmanager
add catcher.py
working on get_mem_percentage_cmd
finish get_mem_percentage_cmd function, and use cmdloop to test
delete useless files.
ignore components/curveanalyzer/sip*
fix loadAll() for pluginmanager
ignore .repoproject directory
add module instance to the mainwindow.
modify mainwindow, curveanalyzer
update  curveanalyzer module.
update curveanalyzer and test.
update .gitignore and remove temp files.
fix paintEvent for Curveanalyzer
use QJson library to parse data from python.
add legenditem
update curveanalyzer and test.
fix a few bugs.
give up QJson.
Merge branch 'feature/curveanalyzer' of github.com:pbesedm/atop-gui into feature/curveanalyzer