Moved global constants into class constants and updated all references
Moved global constants to class constants
Missed a couple SYSTEM_ prefixes
Docblock fix
Quote shell argument with escapeshellarg()

Currently, the call to "scp -t" or "scp -f" just uses naive quoting - i.e. a couple of quote marks are thrown in.

But, this can easily be escaped from - if the filename has a quote mark of its own in it, for example.

e.g. if the filename is as follows, then bad things will happen:

 ";rm -rf /

Instead, escapeshellarg should be used, to make sure it gets escaped properly.
SCP: Add missing space after case statement.
Some tests for crypt_random_string().
Added SSH_AGENT_FAILURE constant back in
Merge pull request #528 from bantu/scp-case

SCP: Add missing space after case statement.

* bantu/scp-case:
  SCP: Add missing space after case statement.
Merge branch 'master' into php5

* master:
  SCP: Add missing space after case statement.
Merge pull request #527 from DavidAnderson684/patch-2

Quote shell argument with escapeshellarg()

* DavidAnderson684/patch-2:
  Quote shell argument with escapeshellarg()
Merge branch 'master' into php5

* master:
  Quote shell argument with escapeshellarg()
Merge pull request #524 from cnelissen/SystemPackageConstantsFix

System package constants fix

* cnelissen/SystemPackageConstantsFix:
  Added SSH_AGENT_FAILURE constant back in
  Missed a couple SYSTEM_ prefixes
  Moved global constants to class constants
Use assertArrayNotHasKey().
Merge pull request #530 from bantu/random-tests

Some tests for crypt_random_string().

* bantu/random-tests:
  Use assertArrayNotHasKey().
  Some tests for crypt_random_string().
crypt_random_string() -> Random::string()
Merge pull request #530 from bantu/random-tests

Some tests for crypt_random_string().

* bantu/random-tests:
  Use assertArrayNotHasKey().
  Some tests for crypt_random_string().
Merge branch 'master' into php5

* master:
  Use assertArrayNotHasKey().
  Some tests for crypt_random_string().
Merge pull request #533 from bantu/random-tests-php5

Some tests for crypt_random_string().

* bantu/random-tests-php5:
  crypt_random_string() -> Random::string()
Merge pull request #523 from cnelissen/FilePackageConstantsFix

File package constants fix

* cnelissen/FilePackageConstantsFix:
  Docblock fix
  Moved global constants into class constants and updated all references