Global vendor dependency note

[soullivaneuh]

Wait puli/cli#21 (comment) reaction.

Some edge case issues can appear while running php-cs-fixer from a global composer installation.

• Update the Troubleshooting note about conflicts. Recommend to use the .phar binary.
• Deprecate (minor) and remove (major) the custom autoloader.

[soullivaneuh]

Or also test this: FriendsOfSymfony/FOSRestBundle#1523 (comment)

[realityking]

Have you considered releasing it as a phar file to avoid these conflicts completely?

[soullivaneuh]

@realityking Yes, I just need time I don't have currently.