#606 tooltip and tip typos

[John R. Jackson]

The attached patch corrects a number of items in the tips and tooltips:

• fixes spelling errors
• fixes grammatical errors (e.g. duplicate words)
• changes single quotes to double quotes for consistency
• removes extraneous blanks, added some blanks for consistency
• changes letter case for consistency
• changes to common wording in some cases
• changes dialog references to standard "Menu|Item" format
• fixes dialog references to match the actual Menu and/or Item text
• verifies/fixes references point to the desired dialog

The patch applies against the current tip (6319:5b981d82db02). It can also be applied to the GTK3V2MAIN branch if you either hand edit the patch and change "genhelp.json" to "tooltiptext.json" or enter "app/help/tooltiptext.json" when patch asks "File to patch:".