Add support for numbers in account names

[lockjs]

Previosuly given the account name Assets:Bank:Santander-123 auto complete would suggest Assets:Bank:Santander-

If the account name was Assets:Bank:Santander-123-Current-Account then auto complete would suggest Assets:Bank:Santander- and -Current-Account

The updated regexp prevents the account name being split so that Assets:Bank:Santander-123-Current-Account will be suggested

[Lencerf]

Since Beancount actually allows any non-whitespace unicode characters in the account name, maybe [A-Za-z:]+\\S+|\"([^\\\\\"]|\\\\\")*\" is a better choice?

[lockjs]

I Agree, seems like a better option and would resolve #20

I'll update the pull-request tomorrow.

Do you want me to bump the version number as well?

[Lencerf]

@lockjs Thanks!
I will handle the version number and update README.

[lockjs]

Updated the regex as you suggested.

I've also modified the language file to correctly highlight account names. You can see the non-ascii charachters weren't highlighted in the example in #20