Supported little endian for MIPS
Don't DES-encrypt priv keys without a passphrase

Per https://www.openssl.org/docs/crypto/pem.html, specifying to encrypt
a private key with DES *without* providing a passphrase causes OpenSSL
to prompt for the passphrase to use on the console -- which is
problematic for GUI applications which generally lack a console.

This modifies the behavior of RSAKeyImpl::save() so that DES encryption
of private keys will not be attempted unless the passphrase argument is
non-empty. This will also suppress OpenSSL's prompting for that
passphrase on the console.

Also added a case to the test suite.
Fix RSAKey constructor documentation.

The two RSAKey constructors which take existing keys (one from a
stream, the other from a string) have incomplete and ambiguous
documentation.

This change improves the header documentation to reflect that:
 1. Decryption is supported using a private key (existing doc says you
    can "only" sign if a private key is present),
 2. Clarify that public key not needed when private key is present.
Update README.md
Update README.md
make NetworkInterface working under XP

on >= Vista NetworkInterface works, but if you try under XP you have ifIndex always not setted: if you compile with XP SP1 defines you get code working on >=XP
RESERVER_QUERY update

in function setQuery, or when you have to use encode internally, is used RESERVED_QUERY that is only # if you have a query with / the character is encoded, and I think you don't want
Merge pull request #568 from johnboy2/develop

Don't require RSA key passphrases on save
Merge pull request #570 from micheleselea/develop

make NetworkInterface working under XP
Merge pull request #566 from mar-na/patch-3

Supported little endian for MIPS
BugFix Missing parenthesis
Merge pull request #572 from micheleselea/patch-1

BugFix Missing parenthesis
Merge remote-tracking branch 'upstream/develop' into develop