add missing files and allow PHP 7.3+

[remicollet]

• remove time (unneeded, added automatically when running "pecl package")
• remove unneeded md5sum (also automatically added)
• allow PHP 7.3
• require pear 1.10 (minimal version with PHP 7 support)
• add missing files

[amishmm]

Any reason that you deleted this PR? Because I had not yet merged it.

[remicollet]

Because it conflicts with your update to 2.2.2 (most relevant remaining part being md5sum removal)

[amishmm]

Ok will implement changes manually. Thanks.