NEXUS-2450: Maven1 reposes will be asked for EJBs

Nexus doing the "conversion" from M2 to M1 path does not have
all the knowledge about requested artifact, like it's packaging
(it's just been asked for). This change adds a small "twist" to
Nexus layout converting shadows, and the "ejbs" folder will be asked
too before giving up a request. While methods now
return List of paths (instead of just one path as before), nothing
changes and almost every method except the doRetrieveItem will
make use only of the first element of the returned list, yielding
in no change. The doRetrieveItem method will use "extra" paths,
and will iterate of the list of paths trying to get response,
ultimately failing with INFex.
[NEXUS-5651] Send 401 in case of an AuthroizationException and user not authenticated (not logged in)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5651] Filter "/service/siesta/**" through  "noSessionCreation,authcBasic" filters

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5651] Introduce FilterChain, a mapping between path pattern and a filter expression

+ convenience guice module for easy binding

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5651] Map "/service/siesta/**" ->  "noSessionCreation,authcBasic" filters

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
add system property via nexus.properties
NEXUS-5660 - java.net.preferIPv4Stack=true should be set by default in case Java 7+ or JMX is used with Nexus
Move timeline/feeds UI from core to plugin
Fix edge cases for classnames (no namespace)
Add events for plugins to add to or change the server settings view
Merge branch 'master' into NEXUS-5660_preferIPv4Stack
Typo nexus.anonynmous -> nexus.anonymous

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
NEXUS-2450: NPE fix

Initial implementation invoked parts it should not invoke
even with null result, causing NPE.

Problem was badly located logic within the for-loop.
move system property to wrapper.conf
NEXUS-5660 - java.net.preferIPv4Stack=true should be set by default in case Java 7+ or JMX is used with Nexus
trying out this setting for ITs on a Bamboo feature build
NEXUS-5660 - java.net.preferIPv4Stack=true should be set by default in case Java 7+ or JMX is used with Nexus
NEXUS-5621: Blocking routing rules are not enlisted in describe

the "appliedMappings" contains both INCLUSIVE and EXCLUSIVE rules
when asked for describe a given request, but BLOCKING mappings
were not enlisted

This simple change makes sure those are enlisted too, making
it easier to detect why something is not served up (in case
BLOCKING rules are used at all).
CR feedback, added comment to new System property on ITs
NEXUS-5660
add new 'persistent' property allowing for tooltips that remain open after focus is lost
NXCM-5147 - Resolve Technical Debt introduced by borrowing of helpText code in CLM plugin
[NEXUS-5662] Add servlet filter to add userId to MDC
Merge pull request #804 from sonatype/NEXUS-5660_preferIPv4Stack

REVIEW: NEXUS-5660 add java.net.preferIPv4Stack system property via nexus.properties
minor layout tweak discussed with @ben during testing of NEXUS-5483