doc: minor formatting fixes
TS-2172: Explicitly use subdir-objects in automake init

This avoids warnings from automake 1.14 and generates correct configure
script.
sdk docs: fix links & formatting in preface
TS-2172: automake subdir-objects requires AM_PROG_CC_C_O
TS-2173: RECD_COUNTER type is missing in setTokenValue()

After applied "TS-1740: Improve precision of stats values" patch,
each token will keep its original type instead of forcing to RecFloat.

So we should update setTokenValue() to deal with RECD_COUNTER case.

Signed-off-by: Yunkai Zhang <qiushu.zyk@taobao.com>