Fixes for patch scaling and V_FLIP usage

The following issues are fixed by this branch:

• a patch using both scaling and V_FLIP does not appear in the "correct" place on the screen. Thanks to LJSonic for pointing this out to me on 'fun
• Scaled and/or V_FLIPed patches wrap at the left/right screen edges even though they're not supposed to. V_FLIP patches at these edges may also crop the wrong side of the patch if they're at the right edge.

Added 3 new commits:

• 5dd0e533 - Removed unused "supdate" variable
• a567ce8e - Merge branch 'master' into next
• de2d327d - Merge branch 'next' into patch-scaling-flip-fix

Added 19 new commits:

• 0953c943 - travis-ci: try osx building
• 73dd5cd8 - travis-ci: add brew packages
• 8d36a77e - travis-ci: libpng, not libsdl
• dfa41ed8 - travis-ci: drop libpng for osx
• 9162e7da - travis-ci: move dist setting to top
• 23c9892f - travis-ci: fixup os list
• 0c9081f7 - cmake: try to fixup mac build
• dadf8e12 - cmake: remove fixed HWRENDER define
• 2165c680 - travis: add -Wno-unknown-warning-option
• 18f51b34 - build: more mac fixes
• fc1d7145 - travis: fixup xml
• 71229085 - travis: matrix is not correct
• 9bc6ce3d - travis: steal SDL2 dmg for Mac build
• 2c4a27c7 - macosx: let fix linking to SDL frameworks
• 077781cc - macosx: drop CoreFoundation linking
• 0f853640 - macosx: We need CoreFoudation for SDLMain
• a3c01ea6 - Merge branch 'travis-ci'
• c23d971b - Merge branch 'master' into next
• 583ffd25 - Merge branch 'next' into patch-scaling-flip-fix

Added 13 new commits:

• 1108a529 - Check change in ceilinglightsec for markceiling code, not floorlightsec
• a7a7de61 - Merge branch 'ceilinglighting-fix' into 'next'
• 51aa7692 - Merge branch 'master' into next
• 75f65c4d - using abs() on unsigned have no effect
• 0fe6ee53 - cleanup abs warnings
• 7e07d2d7 - travis-ci: reenable -Werror
• b169529d - switich to do the angle math in signed, then run it thur abs()
• 10cc421f - travis: add all/extra warnings
• d9053696 - removed/remline ununsed code
• f9411982 - Merge branch 'travis-ci' into 'master'
• de630d0c - appveyor: let check warnings as well
• 9286e303 - Merge branch 'master' into next
• 44afedd8 - Merge branch 'next' into patch-scaling-flip-fix

Added 4 new commits:

• 3812b6bc - the abs() is necessary; force unsigned shift and signed result
• 690b65b4 - "Sonic can now become Super Sonic" exists again
• fc8e7728 - I meant to extend this to 4 seconds but forgot
• 121f144e - Merge branch 'next' into patch-scaling-flip-fix

mentioned in commit 042331ed

Status changed to merged