[Security][Acl] Issue #5787 : Added MutableAclProvider::deleteSecurityIdentity

Code style fix and documentation typo
adds support for PTY mode
adds convenience method mustRun
attempts to fix tests on Travis
adds cache for isPtySupported()
remove deprecated constraints calls (Min, Max, MaxLength, MinLength)
Fix finder date constraints and tests
Consider KERNEL_DIR setting as relative to the PhpUnit XML file if it does not point to a directory (relative to the current cwd)
Changes the form icon in the toolbar to be pixel perfect.
[ExpressionLanguage] throw exception when parameters contain expressions
[Validator]Fixed getting wrong msg when value is an object in UnexpectedTypeException
Refactor common code and reduce nesting
allow TraceableEventDispatcher to reuse event instance in nested events
Add missing lithuanian validator translations
minor #9749 [Validator] Add missing lithuanian validator translations (asarturas)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #9749).

Discussion
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[Validator] Add missing lithuanian validator translations

| Q             | A
| ------------- | ---
| Fixed tickets |
| License       | MIT

Commits
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bebb55c Add missing lithuanian validator translations
bug #9750 allow TraceableEventDispatcher to reuse event instance in nested events (evillemez)

This PR was merged into the 2.3 branch.

Discussion
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allow TraceableEventDispatcher to reuse event instance in nested events

| Q                       | A
| -------------            | ---
| Bug fix?             | yes
| New feature?      | no
| BC breaks?        | no
| Deprecations?    | no
| Tests pass?       | yes
| Fixed tickets      | #9710, #9727
| License              | MIT

Commits
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454ce16 allow TraceableEventDispatcher to reuse event instance in nested events
bug #9722 [Validator]Fixed getting wrong msg when value is an object in Exception (aitboudad)

This PR was merged into the 2.3 branch.

Discussion
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[Validator]Fixed getting wrong msg when value is an object in Exception

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT

Commits
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cdb5ae0 [Validator]Fixed getting wrong msg when value is an object in UnexpectedTypeException
renamed validators.ua.xlf to validators.uk.xlf

ISO 639-1 code for Ukrainian is "uk"
bug #9674 [2.2][Form] rename validators.ua.xlf to validators.uk.xlf (craue)

This PR was submitted for the 2.2 branch but it was merged into the 2.3 branch instead (closes #9674).

Discussion
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[2.2][Form] rename validators.ua.xlf to validators.uk.xlf

| Q             | A
| ------------- | ---
| Fixed tickets | --
| License       | MIT

The ISO 639-1 code for Ukrainian is "uk".

Shall I open separate PRs for newer branches as well, or can this be merged into them?

Commits
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fe6995d renamed validators.ua.xlf to validators.uk.xlf
added ExpressionVoterTest