Implement stateless non-interactive cli_wallet usage

[nemothenoone]

./cli_wallet unlock 1qaz get_private_key wqdasfadf

Output the result of the work in the order of pushing commands.

[AKorpusenko]

A way to implement this is to add a special program option. So for instance we can add program option called "commands". If cli_wallet is run this way: ./cli_wallet --commands="do_this&&do_that", then cli_wallet will execute command in sequence and will print result output of the commands execution in sequence also. By the way interactive mod will be disabled, so after it will immediately terminate.

[AKorpusenko]

Implemented option to run cli_wallet in non-interactive mode (commits: 1cdadf2 and 6a4c650). Also fc/rpc/cli is needed to be changed.

[AKorpusenko]

1. Made a commit to FC. (Look this https://github.com/GolosChain/fc/blob/161-impl-non-interactive-cli-wallet/include/fc/rpc/cli.hpp#L37) It isn't final version.
2. Refactored one place of code to save encapsulation.

[AKorpusenko]

• Made a commit to FC (GolosChain/fc@bd0b507). There have been made only one small fix.

• Next what about cli_wallet:

1. Removed some superfluous checks.
2. Fixed bug with wrong execute/output order: replaced std::map with std::vector of commands. They are executed one by one in the same order as are presented in "commands" string.
3. Some blocks of code (parsing and one by one execution) have been separated and encapsulated into functions.

[AKorpusenko]

@nemo1369 , please write how do the command's output should look like. Now it looks like:
"command output".

[AKorpusenko]

Refactored string parsing and command string storing way.
Asking for a code review @nemo1369 @kotbegemot

[nemothenoone]

@AKorpusenko Build failure is still an issue: https://travis-ci.org/GolosChain/golos/builds/269897507

[VIM-Arcange]

Why not allow cli_wallet to execute a script (i.e. a list of commands put in a text file)
ex: ./cli_wallet --script=filename

[kotbegemot]

The option ./cli_wallet --script=filename can be seen in the future.
You can do without HF.

[VIM-Arcange]

You can do without HF.

Of course. I was just throwing the idea ;)