Implement faster DARE solver

Now that SLICOT is no longer used, the slycot, slicot, and clapack
dependencies were removed. Furthermore, the Fortran build rule and f2c
were removed since SLICOT was the last Fortran dependency.

The last usage of Controllability() was replaced with a DARE error
message print, and the Controllability() function was removed.

Fixes #30.

WORKSPACE

@@ -429,13 +429,6 @@ new_local_repository(
     path = "/usr",
 )
 
-new_git_repository(
-    name = "slycot_repo",
-    build_file = "@//debian:slycot.BUILD",
-    commit = "5af5f283cb23cbe23c4dfea4d5e56071bdbd6e70",
-    remote = "https://github.com/avventi/Slycot.git",
-)
-
 # TODO(Ravago, Max, Alex): https://github.com/wpilibsuite/opensdk
 http_archive(
     name = "arm_frc_linux_gnueabi_repo",
@@ -516,23 +509,6 @@ http_file(
     urls = ["https://software.frc971.org/Build-Dependencies/libusb-1.0.21-windows.tar.xz"],
 )
 
-# The data tarball of the same-named Debian package.
-http_archive(
-    name = "f2c",
-    build_file = "@//debian:f2c.BUILD",
-    sha256 = "2c677437f8217a2e2b23e41b33995d0571644fc1bea46de858f8913a5053e3f4",
-    url = "https://software.frc971.org/Build-Dependencies/f2c_20100827-1_amd64.xz.tar.xz",
-)
-
-# Downloaded from http://www.netlib.org/clapack/.
-http_archive(
-    name = "clapack",
-    build_file = "@//debian:clapack.BUILD",
-    sha256 = "6dc4c382164beec8aaed8fd2acc36ad24232c406eda6db462bd4c41d5e455fac",
-    strip_prefix = "CLAPACK-3.2.1/",
-    url = "https://software.frc971.org/Build-Dependencies/clapack-3.2.1.tgz",
-)
-
 http_archive(
     name = "postgresql_amd64",
     build_file = "@//debian:postgresql_amd64.BUILD",