Add button tooltips need tweaking

1) When "Add" button is disabled

a) Tooltip should be capitalized
b) If there is more than one sentence, punctuation should be included
c) Text should be replaced with something more appropriate
e.g. instead of 'add files after cursor points' something like "Select cursor position before adding files" or "To enable add cursor in the Show" or smth. else

2) When "Add" Button is enabled, the text in tooltips should be redesigned:

a) Tooltip should be capitalized
b) If there is more than one sentence, punctuation should be included
c) Text should be replaced with something more appropriate
e.g. instead of 'add files after cursor points' something like "Add selected files" or smth. more appropriate