Close #2428

Close #2434
Close #2261
Close #2262
Close #2386

Closes #2261
Closes #2262
Closes #2386

Refactor deprecated PHPUnit_Framework_TestCase::getMock() calls

Improve the phpdoc in Connection

Improve return type's phpdoc because it wasn't clear from the phpdoc or the online documentation what would happen if no row was found.

Removed nearly all call_user_* from core( not drivers )

Add testcase for limit/offset when selecting from a subselect

Remove PHP 5.5 support

Deterministic results for ModifyLimitQueryTest

Add error code mapping for "no default value" to MySQL driver

Use implemented method instead of duplicate implementation

When following error message is shown, then it will get converted to the
correct Exception classs of NotNullConstraintViolationException:

  PDOException: SQLSTATE[HY000]: General error: 1364 Field '...' doesn't have a
  default value

[Documentation] Extend Events documentation

Json unflawed Type (DDC-3863)

Fixing method name 'rollBack'

Fix SQL queries numbering in test failure output

For example if the DebugStack SQL logger contains 3 queries, then we want an output like this:
```
3. <query 3>
2. <query 2>
1. <query 1>
```
not like that:
```
4. <query 3>
3. <query 2>
2. <query 1>
```

Add more information for failed queries in tests

Fluent methods in QueryBuilder are now documented as returning `$this`

Catch Throwable in Connection::transactional()

fix grammar in DBALException messages

- have forgot -> have forgotten
- larger or equal to 0 -> larger than or equal to 0

Remove arbitrary line number from github link