ASM 4.0 is generally compatibile with Java 7 classfiles, particularly
including 'invokedynamic' instructions. This is important when
considering that Spring's component-scanning support is internally
ASM-based and it is increasingly likely that component classes having
invokedynamic instructions may be encountered and read by ASM.
This upgrade, then, is primarily preventive in nature.

Changes include:

 - upgrade from ASM 2.2.3 to ASM 4.0

 - adapt to ASM API changes as necessary throughout spring-core,
   resulting in no impact to the public Spring API.

 - remove dedicated spring-asm module

 - use new :spring-core:asmRepackJar task to repackage
   org.objectweb.asm => org.springframework.asm as per usual and write
   repackaged classes directly into spring-core jar

The choice to eliminate the spring-asm module altogether and instead
inline the repackaged classes directly into spring-core is first to
eliminate an otherwise unnecessary second jar. spring-core has a
non-optional dependency on spring-asm meaning it is always on the
application classpath. This change simplifies that situation by
consoliding two jars into one. The second reason for this choice is in
anticipation of upgrading CGLIB to version 3 and inlining it into
spring-core as well. See subsequent commit for details.

Issue: SPR-9669