paypro: example - use strict paypro headers.
Made the error message when we encounter an unknown script pubkey more clear.
Revised error message per feedback on PR.
paypro: fix readme file for better explanation.
paypro: example - add extra arguments for experimentation.
paypro: example - explain extra arguments in readme file.
paypro: example - add --address and --pubkey options. document in readme.
paypro: example - add privkey option. refactor.
paypro: example - remove some comments.
paypro: example - fix request method.
paypro: example - allow user to set options when using example as a module.
paypro: example - allow more modularity concerning options.
paypro: example - document modular usage of example.
paypro: example - fix customer createTX for browser.
paypro: example - remove old createTX.
paypro: example - sign customer transaction after output scripts are altered.
Update Transaction.js

Global leak fix
fix logging
fix logging 2
fix bug - 0 fee is not working!

if the user pass 0 fee (in fee or feeSat arguments) - there's a bug in the program that will add fee even if specified 0 fee:

- in case fee or feeSat is 0 the if statement `if (opts.fee || opts.feeSat)` will be false.
from some reason `0 || undefined` in js returns `undefined` and in case a user set the fee to 0 in options this condition will not happen. 

- second fix: `var feeSat = this.givenFeeSat ? ...` fixed since if `this.givenFeeSat` is 0 the condition will return false (and we want true in this case) since `0 ? true : false` will return `false` in js language.