(cherry picked from commit 107f0eb3)

(cherry picked from commit c229ddd5)

(cherry picked from commit df1e00fd)

(cherry picked from commit 1e2231fb)

(cherry picked from commit 6bd416bd)

XWIKI-7163: Resolving of an extension artifact from a maven repository seems to cause unexpected persistence of its POM information
* no git commit -a is not always enough...

(cherry picked from commit 647846cb)

XWIKI-7163: Resolving of an extension artifact from a maven repository seems to cause unexpected persistence of its POM information
* refactor a bit

(cherry picked from commit 2420ae72)

(cherry picked from commit a49e6dd2)

(cherry picked from commit 0f60183f)

XWIKI-7163: Resolving of an extension artifact from a maven repository seems to cause unexpected persistence of its POM information

(cherry picked from commit 11fb378d)

(cherry picked from commit 76ec6669)

* make sure status log can never be null

(cherry picked from commit 1137e1be)

(cherry picked from commit 44241dbc)

(cherry picked from commit 9ca53a03)

(cherry picked from commit e3511df4)

(cherry picked from commit 226e652a)

 - Simplify and improve the signature verifier

XCOMMONS-566: Add helpers for direct access to subject and authority key identifier from X509CertifiedPublicKey

[misc] Reverting previous cleanup. It is included in standard JRE but it's a very old version, even in Java 8...