Try to expand text before point, using multiple methods.
The expansion functions in `hippie-expand-try-functions-list' are
tried in order, until a possible expansion is found. Repeated
application of `hippie-expand' inserts successively possible
With a positive numeric argument, jumps directly to the ARG next
function in this list. With a negative argument or just C-u,
undoes the expansion. (fn ARG)