Replace :edit with :read to read in the log

There are some hardly predictable results related to 'modeline' option.
Instead of just disabling the option also :read file and remove first
(empty) line from original buffer instead of :editing the file.
Merge pull request #25 from int3/disable-modeline-processing

Replace :edit with :read to read in the log

There are some hardly predictable results related to 'modeline'
option. Instead of just disabling the option also :read file and
remove first (empty) line from original buffer instead of
:editing the file.

Fixes #22.