disassemble should skip if target file is newer than the source

[yegor256]

Currently, the disassemble goal processes all files, even though some of them may be skipped: when target file is newer than the source one. The same is true for the assemble goal.

[yegor256]

@volodya-lombrozo please, check this one

[volodya-lombrozo]

@yegor256 It might be a good optimization, indeed. Does this slowdown influence you build much?

[yegor256]

@volodya-lombrozo this is just a common practice in Maven: build incrementally, skipping duplicate builds. Of course, it will save some time (especially on large projects).