put all (int32_t) to WELS_ROUND to minimize possible mismatch on double-float calculation on different machines and remove some unnecessary (int32_t)
update the minimum quant limiation as 10. quant 4 can't avoid overflow
Merge pull request #873 from ruil2/enc_quant_v1.0

update the minimum quant limiation as 10
expand the bs buffer size
Merge pull request #875 from huili2/bug_fix_dec_bs_buffer

Bug fix dec bs buffer expand
clean build warning related encoder
Merge pull request #869 from sijchen/rc_fix_101

[Fix] put all (int32_t) to WELS_ROUND
Merge pull request #877 from ganyangbbl/remove_enc_warning

[Fix] clean build warning related encoder