fix up the interface to prepare for testing

Added a "floatsize" method to [pdinfo]
Cleaned up the format specifier for [print] and gui_vmess
Got rid of unnecessary "l" in "%lg"
10 jobs for double-precision-interface in 447 minutes and 55 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test
passed debian_jessie_i386_deb #9973
debian jessie i386

00:40:56

passed debian_jessie_x86_64_deb #9974
debian jessie x86_64

00:36:45

passed debian_stretch_x86_64_deb #9975
debian stretch x86_64

00:48:54

passed osx_10.11_x86_64_dmg #9979
osx v10.11 dmg

00:19:18

passed osx_10.8_x86_64_dmg #9980
osx v10.8 dmg

00:27:14

passed raspbian_stretch_armv7l_deb #9982
raspbian arm stretch

00:55:38

passed ubuntu_14.04_i386_deb #9976
ubuntu v14.04 i386

00:37:33

passed ubuntu_14.04_x86_64_deb #9977
ubuntu v14.04 x86_64

00:33:28

passed ubuntu_16.04_x86_64_deb #9978
ubuntu v16.04 x86_64

00:43:33

passed windows_i386_innosetup #9981
windows i386

01:44:31