Configure whitespaces

[extsoft]

https://stackoverflow.com/questions/3372822/git-trim-whitespace?answertab=active#tab-top

Ask a user to apply this configuration:

[core]
    whitespace = trailing-space,space-before-tab
[apply]
    whitespace = fix

DoD:

1. Must be present in local and global config.
2. Use defaults from the sample above if git's global config has no values.
3. Ask a user "configure whitespaces?" and apply configuration on if the user will agree

[AntonKarabaza]

@extsoft From Git Documentation:

space-before-tab (enabled by default)
trailing-space is a short-hand to cover both blank-at-eol and blank-at-eof
blank-at-eol (enabled by default)
blank-at-eof (enabled by default)

Seems, that we don't need to configure:

[core]
    whitespace = trailing-space,space-before-tab