Add UnsafeSubversionDownloadStrategy
Add UnsafeSubversionDownloadStrategy

There was an UnsafeSubversionDownloadStrategy in a single formula
before, but a) it broke against later changes to
SubversionDownloadStrategy, and b) wasn't available to other formula.

Signed-off-by: Adam Vandenberg <34c2b6407fd5a10249a15d699d40f9ed1782e98c@gmail.com>

gregory-nisbet/brew,hanxue/linuxbrew,rwhogg/brew,mistydemeo/homebrew,JCount/brew,sjackman/homebrew,mahori/brew,claui/brew,ilovezfs/brew,claui/brew,MikeMcQuaid/brew,gordonmcshane/homebrew,maxim-belkin/brew,bfontaine/brew,ilovezfs/brew,maxim-belkin/brew,bfontaine/brew,reitermarkus/brew,alyssais/brew,toonetown/homebrew,aw1621107/brew,MikeMcQuaid/brew,pseudocody/brew,palxex/brew,pseudocody/brew,Homebrew/brew,toonetown/homebrew,Homebrew/brew,zmwangx/brew,gregory-nisbet/brew,vitorgalvao/brew,bfontaine/brew,reelsense/brew,aw1621107/brew,Linuxbrew/brew,rwhogg/brew,hanxue/linuxbrew,staticfloat/brew,vitorgalvao/brew,JCount/brew,sjackman/homebrew,konqui/brew,mgrimes/brew,nandub/brew,mistydemeo/homebrew,reitermarkus/brew,claui/brew,konqui/brew,hanxue/linuxbrew,vitorgalvao/brew,tonyg/homebrew,gordonmcshane/homebrew,zmwangx/brew,DomT4/brew,mgrimes/brew,JCount/brew,tonyg/homebrew,Homebrew/brew,mahori/brew,amar-laksh/brew_sudo,Linuxbrew/brew,aw1621107/brew,Homebrew/brew,amar-laksh/brew_sudo,jmsundar/brew,pseudocody/brew,nandub/brew,zmwangx/brew,muellermartin/dist,alyssais/brew,claui/brew,konqui/brew,staticfloat/brew,tonyg/homebrew,muellermartin/dist,gregory-nisbet/brew,reelsense/brew,reelsense/brew,gordonmcshane/homebrew,jmsundar/brew,mahori/brew,DomT4/brew,AnastasiaSulyagina/brew,sjackman/homebrew,reitermarkus/brew,EricFromCanada/brew,vitorgalvao/brew,jmsundar/brew,staticfloat/brew,mistydemeo/homebrew,reitermarkus/brew,AnastasiaSulyagina/brew,mahori/brew,AnastasiaSulyagina/brew,maxim-belkin/brew,palxex/brew,toonetown/homebrew,nandub/brew,Linuxbrew/brew,mgrimes/brew,ilovezfs/brew,DomT4/brew,JCount/brew,EricFromCanada/brew,nandub/brew,MikeMcQuaid/brew,alyssais/brew,amar-laksh/brew_sudo,EricFromCanada/brew,konqui/brew,muellermartin/dist,palxex/brew,Linuxbrew/brew,sjackman/homebrew,EricFromCanada/brew,DomT4/brew,MikeMcQuaid/brew,rwhogg/brew