Upgrade to slf4j 1.7.13

10th of November, 2015 - Release of SLF4J 1.7.13

Fixed LoggerFactory initialisation problem in presence of SecurityManager denying "createSecurityManager" runtime permission. See SLF4J-324 for further details.

Fixed issue with BasicMDCAdapter leaking MDC information to non-child threads. This problem was reported by Lukasz Cwik in SLF4J-316 who also provided the relavant pull request.

More robust handling of ill-formatted input strings by SLF4JBridgeHandler. This issue was reported in SLF4J-337 by Rodolfo Udo Labsch.

House cleaning of our project's Maven pom.xml files, an initiative undertaken by Jeremy Landis.

Added getAdditivity() method method in Category class in the log4j-over-slf4j module. This addition was requested by Milo Felipe SLF4J-309 with Dimitrios Liapis providing the relavant pull request.

Added the assertLog(boolean, String) method in the Category class, in module log4j-over-slf4j.

In the log4j-over-slf4j module, removed misplaced Layout.java file. This issue was reported in SLF4J-218 by Joshua M Steward with Alfredo Ramos providing the relavant pull request.