Do not expect failure for test issue-19

If php-mode fails to properly align arrows for chained method calls
then we want to know that.

Github-issue: 81
Do not trigger search error in php-mode-test-issue-19

We search for the string ‘$object->’ to determine if its position
matches the arrow on the next line.  Because we test this in different
contexts (e.g. in methods, in closures, at the top level) we search
for the string in a loop.  When we reach the end of the buffer,
however, search-forward returns an error because there are no more
‘$object->’ strings to find.  This patch changes the search so it does
not raise the error but only returns nil at the end, causing the loop
to end normally.

Github-issue: 81
Fix chained method alignment

Commit f933ec2d removed the cc-mode setting for ‘statement-cont’ but
we never re-introduced it when implementing the different PHP styles.
That breaks the alignment of chained methods across different lines.
This patch fixes this by re-introducing ‘statement-cont’ to each style
and by giving ‘brace-list-intro’ and ‘brace-list-entry’ proper values
so that methods are correctly aligned in the different contexts
presented in the issue-19 test.

This patch causes php-mode-test-issue-19 to pass successfully.

Github-issue: 81
Merge branch 'issue-81'

* issue-81:
  Fix chained method alignment
  Do not trigger search error in php-mode-test-issue-19
  Do not expect failure for test issue-19