Working, but drawing is not perfect
Better implementation, spacing now correct, drag&drop working.

Inputs tab still needs spaces converted to &nbsp;
Code cleanup
Corrected list items width (long items were wrapping)
Refactored inputs tab, same system as mixes tab (grouping of lines)
Fixed incorrect spacing for first list item
Reverted to original code (both work)
Code refactoring
Added documentation
Prevent drag&drop between inputs and mixers
Cosmetic changes
Merge branch 'upstream/next'
Reverted commit 8c5fc3a01fa611033207fe11df875d3c894334a8 (which prevented moving second mixer to the first line)
Merge pull request #999 from projectkk2glider/mixes_tab_dragdrop_bug_issue_997

Improvement of inputs and mixers tabs in companion