RSA: auto-detect public keys vs private keys
RSA: update unit test file
BigInteger: speedup internal mode slightly

Changes should yield a slight speedup per the analysis at https://github.com/phpseclib/phpseclib/pull/317#issuecomment-42122335
ASN1: make File_ASN1 accept int primitives and not just Math_BigInteger objects when an integer is expected

The code to convert the regular integer type into the appropriate format could all just be in-line'd when an integer primitive is used but this approach is easier to read.
ASN1: let strings in as well
Merge pull request #336 from terrafrost/asn1-int

ASN1: make File_ASN1 accept int primitives and not just Math_BigInteger ...

* terrafrost/asn1-int:
  ASN1: let strings in as well
  ASN1: make File_ASN1 accept int primitives and not just Math_BigInteger objects when an integer is expected
Merge pull request #335 from terrafrost/internal-mode-speedup

BigInteger: speedup internal mode slightly

* terrafrost/internal-mode-speedup:
  BigInteger: speedup internal mode slightly
SFTP: add file_exists, is_dir and is_file functions

also expand caching layer
SFTP: add support for recursive nlist and rawlist
SFTP: Rudimentary tests for file_exists(), is_file(), is_dir().
SFTP: switch from using file existence cache to stat cache, like PHP

also add a few new functions - is_link and filesize
SFTP: use_cache -> use_stat_cache
Merge pull request #338 from terrafrost/sftp-changes-20140510

SFTP: add file_exists, is_dir and is_file functions

* terrafrost/sftp-changes-20140510:
  SFTP: use_cache -> use_stat_cache
  SFTP: switch from using file existence cache to stat cache, like PHP
  SFTP: add support for recursive nlist and rawlist
  SFTP: add file_exists, is_dir and is_file functions
SFTP: stat cache updates
Merge pull request #341 from bantu/sftp-changes-20140510

SFTP: Rudimentary tests for file_exists(), is_file(), is_dir().

* bantu/sftp-changes-20140510:
  SFTP: Rudimentary tests for file_exists(), is_file(), is_dir().
Merge pull request #342 from terrafrost/sftp-statcache-changes

SFTP: stat cache updates

* terrafrost/sftp-statcache-changes:
  SFTP: stat cache updates
SFTP: add more unit tests
SFTP Functional tests: Keep story linear.
SFTP Functional tests: Make use of assertNotSame
SFTP: last commit had a few ommissions