Rename every occurence of prepare with analysis

If you are new to the code the name prepare for everything that is
related to the analysisview can be confusing. Renaming them will make
it easier to see what the classes are being used for
drag'n'drop tracks on analyzeview
starting queuesize is set correctly
add option to analyzse crate/playlist to submenu

this path also does some minor code refactoring
adress rryans comments
merge with kain88de/analysis