"#' + Enter" only works when there is no space / tab before the #'

[sebffischer]

Is your feature request related to a problem? Please describe.
When a line starts with #' and I press enter, the next line also starts with #'.
This does not happen when I am e.g. on a line with
" #' ... "
This is annoying when e.g. documenting R6 Classes.

Describe the solution you'd like
When I press enter on a line whose first 2 non-tab, non-space characters are #', I want
the next line to start with #'.

[sebffischer]

Also syntax highlighting is broken for roxygen2 documentation when the "#'" is preceded by tabs and spaces. Was this also fixed by the commit?