Improve OSGi manifest generation

The OSGi Manifest for the different jackson projects show some discrepancies with each other and the usual OSGi conventions.

1- The Bundle-SymbolicName for jackson-annotations and jackson-jaxrs-json-provider have changed. Going from only the project name to being prefixed by com.fasterxml.jackson. This shouldn't affect anyone that follows the OSGi recommendation of using Import-Package instead of Require-Bundle, but we use Require-Bundle and therefore had to recompile my OSGi projects.

2- The Bundle-SymbolicName of jackson-core and jackson-databind does not follow the same naming convention as those other 2 projects. This is probably due to the fact that they don't use the FasterXml parent pom, which defines a bunch of things, including OSGi definitions.

3- The projects don't follow the OSGi naming convention. Usually the Bundle-SymbolicName is the same as the top-level java package (I take Eclipse as an example): c.f.j.annotations, c.f.j.core, c.f.j.databind, c.f.j.jaxrs.json. [1]

3- None of the Manifest have a Bundle-RequiredExecutionEnvironment declaration. I think it should at least include the J2SE-1.5 declaration, but JavaSE-1.6 and JavaSE-1.7 are also a good idea to include.

I have not looked at the other projects since these are the only ones I use.

[1] http://wiki.osgi.org/wiki/Bundle-SymbolicName