The current implementation assumes that escripts all have at least
three lines. But according to the escript documentation, comments
on the second line and emulator flags on the third line are all
optional. Thus escripts with only two lines -- shebang on the
first line and code on the second line -- will not run. This commit
fixes the problem by rearranging the escript header parsing logic,
and recognize the escript body on the second line if the header only
contains a line of shebang.

* dgud/testcase_fixes:
  Fix timers
  mnesia: Decrease test times
  Add debug printouts
  wx: Fix failing testcases
  stdlib: Ignore symlink tests on windows

The manual says that an Emacs directive can be placed on the second
line. With this patch that directive is also recognized when selecting
encoding of the script.

Symlinks only partially works on windows 7, ignore those tests
on windows machines for now

According to the documentation, if the second or third line in a
script starts with %%!, then escript will use the rest of the line
as emulator options.  However, previously this was only the case
if the first line started with #!.  This change removes that check,
and unconditionally uses the %%! line if present.

Expect modifications, additions and corrections.

There is a kludge in file_io_server and
erl_scan:continuation_location() that's not so pleasing.