Currently, FeMetaVersion.java is in fe-common, users may forget to copy fe-common.jar when upgrading the service.
It's really dangerous because the data may be corrupted and can not be recovered.
The io related codes may be used by new modules, so It's better to move them to fe-common.
The modification to fe-core is frequent, but there are many generated java files by thrift
will slow down the compilation, so It's better to move thrift generation process to fe-common.
Currently both log4j1 and log4j2 are used, which leads to logs are written to wrong files.
Our modification will remove log4j1 from dependency, use slf4j + slf4j -> log4j2 instead.
This CL mainly changes:
1. Add 2 new FE modules
1. fe-common
save all common classes for other modules, currently only `jmockit`
2. spark-dpp
The Spark DPP application for Spark Load. And I removed all dpp related classes to this module, including unit tests.
2. Change the `build.sh`
Add a new param `--spark-dpp` to compile the `spark-dpp` alone. And `--fe` will compile all FE modules.
the output of `spark-dpp` module is `spark-dpp-1.0.0-jar-with-dependencies.jar`, and it will be installed to `output/fe/spark-dpp/`.
3. Modify some bugs of spark load
