Problem: When using slices there is a mixup of variable name and namespace.
Solution: Recognize variables that can't be a namespace. (Hirohito Higashi)
Problem: ":tabdo windo echo 'hi'" causes "* register not to be changed.
(Salman Halim)
Solution: Change how clip_did_set_selection is used and add
clipboard_needs_update and global_change_count. (Christian
Brabandt)
Problem: Can't define a function starting with "g:". Can't assign a
funcref to a buffer-local variable.
Solution: Skip "g:" at the start of a function name. Don't check for colons
when assigning to a variable.
Problem: It is possible to define a function with a colon in the name. It
is possible to define a function with a lower case character if a
"#" appears after the name.
Solution: Disallow using a colon other than with "s:". Ignore "#" after the
name.
Problem: getreg() does not distinguish between a NL used for a line break
and a NL used for a NUL character.
Solution: Add another argument to return a list. (ZyX)
