Because it is a budren to maintain and LGPL 2.1 does not require
them, but only suggest them:
> To apply these terms, attach the following notices to the library.
> It is **safest** to attach them to the start of each source file
> to most effectively convey the exclusion of warranty; and each
> file **should** have at least the "copyright" line and a pointer
> to where the full notice is found.
https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html#SEC4
Because alignment was all broken and becaues it doesn't improve much
the code readability, but potentially create more complicated diff, we
prefer to unlaign all docblocks.
Third party PDF libraries must now be installed via composer and naturally
via composer autoloading mechanism. Because of that it is not necessary
to specify their path on disk. The usage is simplified and it allows us
to include them in our unit tests.
This also means that from now on PhpSpreadsheet must use composer autoloader
mechanism. The internal autoloading implementation was dropped.
