Forms: added default error message for Form::MIME_TYPE
Fix FileUpload::__toString() when is empty
RobotLoader: ignores ClassName::class syntax [Closes nette/robot-loader#1]
Latte: Parses respects HTML specification for HTML comments tokenization
Latte: improved HTML comments escaping
Latte: BlockMacros: fixed including parent block multiple times [Closes nette/latte#18]
Latte: added protection against innerHTML mXSS vulnerability [Closes nette/nette#1496] (possible BC break)

IE8 for code `<div attr="``foo=bar">` produces invalid innerHTML `<div attr=``foo=bar>`. Adding a space at the end of the attribute forces IE to put quotes around the attribute.

More info:
http://www.nds.rub.de/research/publications/mXSS-Attacks/
http://www.slideshare.net/x00mario/the-innerhtml-apocalypse
Html: added protection against innerHTML mXSS vulnerability [Closes nette/nette#1496] (possible BC break)

IE8 for code `<div attr="``foo=bar">` produces invalid innerHTML `<div attr=``foo=bar>`. Adding a space at the end of the attribute forces IE to put quotes around the attribute.

More info:
http://www.nds.rub.de/research/publications/mXSS-Attacks/
http://www.slideshare.net/x00mario/the-innerhtml-apocalypse
Latte: safeUrl allows colon when URL starts with / ? #  [Closes #1389]
Latte: safeUrl filters semantic attacks like http://nette.org@1572395127
tests: added missing assertions, updated to Tester 1.1
more readable exception strings, typos

Conflicts:
	Nette/ComponentModel/Container.php
	Nette/DI/Compiler.php
	Nette/DI/Container.php
	Nette/DI/ContainerBuilder.php
	Nette/Database/Helpers.php
	Nette/Database/Table/Selection.php
	Nette/Forms/Controls/BaseControl.php
	Nette/Forms/Controls/Checkbox.php
	Nette/Forms/Controls/HiddenField.php
	Nette/Forms/Controls/MultiChoiceControl.php
	Nette/Forms/Controls/RadioList.php
	Nette/Forms/Controls/TextBase.php
	Nette/Latte/Macros/CoreMacros.php
	Nette/Latte/PhpWriter.php
	Nette/Mail/Message.php
	Nette/Utils/Callback.php
	Nette/Utils/Html.php
	Nette/Utils/Validators.php
	tests/Nette/Database/Table/SqlBuilder.addWhere().phpt
	tests/Nette/Database/Table/Table.basic.phpt
Database: added support DateTimeImmutable & DateTimeInterface [Closes #1216]
Database: fixed getting sequence name if it was renamed [closes #1443]
Database: PgSqlDriver reflection search in all current schemas
Fixed detection of composite primary keys [closes nette/database#4]
Database: fixed SqliteDriver
iconv_set_encoding() is deprecated since 5.6.0

5.6.0 breaks loader.php in Nette 2.0
__toString: when is called as method, exceptions are thrown
Travis: enable running tests on PHP 5.6