Adding connection router source files

connection routing algorithms: breadth-first search router, directed search router and timing driven router

Signed-off-by: Elias Vansteenkiste <Elias.Vansteenkiste@ugent.be>
intermediary commit,

in process of porting connection router to VPR 7.0 framework

Signed-off-by: Elias Vansteenkiste <Elias.Vansteenkiste@ugent.be>
intermediary commit

Signed-off-by: Elias Vansteenkiste <Elias.Vansteenkiste@ugent.be>
Merge branch 'master' of https://github.com/EliasVansteenkiste/ConnectionRouter