Closes #112 Slow greedy regex

[harmenwierenga]

When applying fprettify using the --case 1 1 1 1 option, the following code takes a long time to format because of the matching of floating point constants:

program main
   implicit none
   real, dimension(2) :: array
   array = [9.23529879234512349823d-02, 3.34099894387578238101e-01]
   print *, sum(array)
end program main

On my computer, it takes 6.5 seconds to format. With my simplification of F90_NUMBER_ALL_RE, it still takes 3.2 seconds to format. Finally applying the fix from #112, it only takes 0.13 seconds to format.

A part of this PR is already adressed in #99, but it appears to be stalled, and I hope that this small fix is easier to review. I noticed the issue because formatting some files at work took > 5 minutes, and a profiler showed that 99% of the time was spent matching these regexes. Apparently this was also noticed by @Jellby and @zaikunzhang in the past, see issue.