Bugfix: Error in a long flag name for release finish
Function _flags_itemInList refactored.

The function no longer makes use of external commands, making it a bit
faster.
Add functions for overriden flags.

Add the functions to override a voolean flag and also a function to
check if a given value is a valid boolean.
Add override ability
Add override ability
Add override string function
Add override ability
Add override ability
Add override ability
Refactoring of functions.

Refactor the function to override the flags to make them more like the
other functions in the program.
Version bump 1.5.0-dev.17
Merge branch 'feature/set-flags-default-by-env' into develop
Quote the string to check.

When the variable is set to an empty string, it needs to be in quotes.
Modify the squash message
Add flag for extra squash info

Now there is the ability to select whether you want the extra squash
info or not.
Add new flag info
Merge branch 'feature/mod-squash-msg' into develop
Fix usage output

The usage says to install either master or develop, but the script
checks for stable or develop.

Fixes: #67