Fix section order issues for all files

[Girgias]

These issues can be found by using the section-order.php QA script located in doc-base,
and should be fixed similarly to how it is done in #657

[mumumu]

php doc-base/scripts/qa/section-order.php | awk '{print $2}'| awk -F '/' '{print $8}'|sort | uniq -c | awk '{print "  - [ ] " $2 " ("$1 ")"}' | tail -n +2

• event (7) Fix method aliases in Event class #687
• parallel (3)
• pcre (1) Fix issues in pcre directory #723
• pdo (3) Add missing param/return value sections #1459
• snmp (2) Add missing param/return value sections #1459
• soap (2) Add missing param/return value sections #1459

[Girgias]

I went through a couple of them and most of them where straight forward, couple of issues I found:

• ev is a false positive, but I don't understand why it gets picked up by the script (ignore this I thought it was flaging the return section)
• preg_filter() is missing documentation for its parameters (which is surprising, and a doc bug)
• Same for MemCached::setOption()
• SoapClient::__call() the docs mention this is deprecated, but it is not in php-src, and it's missing both docs for its params and return value.
• The MongoDB seem to be all false positive, the bson and tutorial folder needs to be excluded in the script
• runkit7_zval_inspect() needs to have it's array return value explained.
• Similarly, eio_fchown() needs its non void return value explained.

[Girgias]

I've updated the script, it clear a bunch of false positives, but I've also added detection for predefined classes and for "unknown" section roles (some of them might make sense in which case the script will need to be revised again).

[saundefined]

Seems it can be closed =)

[Girgias]

All items have been addressed.