Bugfix in packet_length calculation

One of the bitshifts used to construct tmplen (lines 230-231) was inconsistent with the other expressions:

(input[mypos2++].charCodeAt() << 8)

causing following error:

TypeError: Cannot call method 'charCodeAt' of undefined
    at Object.module.exports.read (/home/scott/dev/keystone/fetch/node_modules/openpgp/src/packet/packet.js:231:16)

Corrected to 

(input.charCodeAt(mypos2++) << 8)
Key generation: do not clear private MPIs for keys without passphrase.
Merge pull request #248 from openpgpjs/clearPrivateMPIs

Key generation: do not clear private MPIs for keys without passphrase.
bump version
add grunt-cli to devDependencies by running npm install --save-dev grunt-cli
Merge pull request #249 from adhintz/master

add grunt-cli to devDependencies
Use svg in travis badge
Add bower support
Fix sorting of primary users
Merge pull request #252 from omeid/master

Add bower support.
Merge pull request #253 from toberndo/fix_getPrimaryUser

Fix sorting of primary users
Upgrade license to LGPL version 3.0 or later.
Add RSA keygen example using WebCrypto Api
map JWK parameters to local BigInteger
Refactor key generation to use callback
* TODO: reactive native web crypto in rsa.js:142
* TODO: generate publicExponent Uint8Array from argument E in rsa.js:148
* TODO: signing with generated web crypto key fails with "Could not find valid key packet for signing in key"
Activate web crypto api (still fails tests)
* Remove api support for safari
* Fix error handling
Fix decoding of JWK. Webcrypto works.
Fix typo
Cleanup promise error handling
Make WebCrypto optional with config.useWebCrypto