[FIX] amount precision bugs

- leading 0's for fraction part disappearing
- first decimal lower than 5 wouldn't result in dropping the decimal
Merge pull request #188 from geertweening/fix/amount_precision

[FIX] amount precision bugs
[DOC] update release notes
[TASK] bump version to 0.9.0-rc5
[TASK] move gulp-bump to devDependencies
[FIX] confusion between precision and min_precision

`precision` expresses precision within the provided value and won't expand it if the max expression of the value is smaller
`min_precision` will expand the value if the max expression of the value is smaller
Correct usage example with surrounding apostrophes
Merge pull request #193 from professorhantzen/patch-1

[FIX] correct usage example with surrounding apostrophes
Fix account root request ledger argument #121
Merge pull request #192 from geertweening/fix/amount_precision

[FIX] confusion between precision and min_precision
[DOC] Correct GUIDE for ledger_closed.
* The event has to be on the remote, not the subscribe request.
[NO MERGE!] Remove signature computation
Request ledger_accept returns the Request, not Remote