Extract tool info into new class, self-update command works now only for phar version
minor #737 Extract tool info into new class, self-update command works now only for PHAR version (keradus)

This PR was merged into the 1.1-dev branch.

Discussion
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Extract tool info into new class, self-update command works now only for PHAR version

It is another approach for #710 - make self-update command works only for PHAR version, great idea by @tucksaun !
It will no mislead users for command which is sometimes available and sometimes missing.

// cc @tucksaun @GrahamCampbell @Seldaek

Commits
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a5bd2f6 Extract tool info into new class, self-update command works now only for phar version
Added an empty return fixer