Added reloading of fallback catalogues when calling addResource() (#7715)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7715
| License       | MIT
| Doc PR        |
Reset all catalogues when adding resource to fallback locale (#7715, #7819)

Slightly refactored testAddResourceAfterTrans()
and replaced costly part with reset all catalogues

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7715, #7819
| License       | MIT
| Doc PR        |
Merge branch '2.2'

* 2.2:
  [BrowserKit] fixed BC break done recently
  [Process] Fix #5594 : `termsig` must be used instead of `stopsig` in exceptions when a process is signaled
  [Console] find command even if its name is a namespace too (closes #7860)
  Rename misprint property (from warmer to finder)
  Reset all catalogues when adding resource to fallback locale (#7715, #7819)
  Added reloading of fallback catalogues when calling addResource() (#7715)
  Re-added context information to log list
  Add This field is missing RU translation

Conflicts:
	src/Symfony/Component/Console/Tests/ApplicationTest.php