SSH2: fix issues with RSA key verification

Sometimes SSH servers will null pad their RSA keys. this null padding
broke Net/SSH2.php's RSA implementation (Crypt/RSA.php's implementation
works just fine). Also, the -3 was counting the initial "\0" of $h
twice so adjust it to -2.
Merge pull request #500 from terrafrost/ssh-rsa-fix

SSH2: fix issues with RSA key verification

* terrafrost/ssh-rsa-fix:
  SSH2: fix issues with RSA key verification
add CHANGELOG.md
update download version in README.me
Merge branch 'master' of https://github.com/phpseclib/phpseclib
SSH2: clarify exec() docblock comment
Merge pull request #503 from terrafrost/bug501

SSH2: clarify exec() docblock comment

* terrafrost/bug501:
  SSH2: clarify exec() docblock comment
Update sami/sami to 2.*
Update phpunit/phpunit to 4.3.*
Update squizlabs/php_codesniffer from 1.5.2 to 1.5.5
Merge pull request #516 from bantu/dev-deps-update

Update development dependencies

* bantu/dev-deps-update:
  Update squizlabs/php_codesniffer from 1.5.2 to 1.5.5
  Update phpunit/phpunit to 4.3.*
  Update sami/sami to 2.*
Updated dependencies
Merge pull request #517 from GrahamCampbell/deps

Updated dependencies

* GrahamCampbell/deps:
  Updated dependencies
Avoid calling fclose(false)

The previous code would always call fclose(false) if the file was not successfully opened - resulting in a PHP notice.
Merge pull request #522 from DavidAnderson684/patch-1

Avoid calling fclose(false)

* DavidAnderson684/patch-1:
  Avoid calling fclose(false)
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().
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 pull request #527 from DavidAnderson684/patch-2

Quote shell argument with escapeshellarg()

* DavidAnderson684/patch-2:
  Quote shell argument with escapeshellarg()