fix bug #657. RPC module frees the msg body while other threads still access that struct to cause the SIGSEGV error.

print the java.library.path variable for debug

fix the bug that the setLocale function return wrong value to cause both the TDengine and Shell fail to launch.#494 #478

format the code

fix issue #642 to add  druid pool support

add support preparedstatement execute batch

update less or equal symbol

udpate jdbcdriver maven repository

taosjdbc-driver have benn published to maven central repository, you can serach from https://search.maven.org or https://mvnrepository.com.

update english single quote and  =< to <=

release taos-jdbcdriver.jar to maven central repo

Fixed bugs relating to timestamps

- Fixed bug when the least significant bits of timestamp may cause time to be converted to 0
- Fixed small display bug with time and sig figs.

update english single quote and less than or equal to <=

taos-jdbcdrvier.jar has deployed to  maven central repo, you can search from https://search.maven.org or https://mvnrepository.com

Fixed bug where errors were printed as numbers instead of the string

# Conflicts:
#	src/util/src/ttimer.c