add code
add docs
remove having problems
modify documents
fixed the symbol "'" in sql operation
change git ignore
add wiki url
remove unuse files
change git ignore
add ODBC test case
Fixed compile in R15B.

R15B introduced some incompatible changes in drive interface. Some
driver callbacks started using ErlDrvSizeT and ErlDrvSSizeT instead of
int. This commit updated callbacks in the driver and provided
compatible fallbacks for old OTP versions.
Move the connection pool scheduler to Erlang.
ignore some files
add keyword mapping in oracle db operation functions.
redefined the information in the document.
Fix the list of integer overflow.

执行数据库操作如下：

db_api:select(stats_session_info, {id, 'in',
[122,157,158,0,128,127,129,255]}).

打印的sql语句如下：

sql=select * from stats_session_info where id in
(122,-99,-98,0,-128,127,-127,-1)
当整数列表中的整数大于等于128时解析出的值会溢出。

整数列表中如果所有的元素值都小于256，类型为ERL_STRING_EXT，以字符串解析，而字符的取值范围在-128~127之间。
Merge branch 'master' of https://github.com/denglf/erlang-db-driver