udpate branching doc
build from dev to master
add test mode
add awk script
support separated test
fix duplicated ph focusing bug for Build()

bug that ph will be choosed twice:
XPT b
XSET x|post=Build('`ph^-`ph^')
`x^
fix mark escaping
run.py fix remove rst
fix preview option of completeopt
add test 60-ph-func-Build-def
add test 60-ph-func-Build-instant
add test 60-ph-func-Build-post
Merge branch 'f.readme' into dev
Merge branch 'f.build' into dev
Merge branch 'f.test' into dev
Merge branch 'f.engine' into dev
Merge branch 'f.pum' into dev