Link against system-provided sqlite3.

--- a/Cargo.toml
+++ b/Cargo.toml
@@ -34,4 +34,4 @@
 
 [dependencies.rusqlite]
 version = "0.15.0"
-features = ["bundled", "functions", "unlock_notify"]
+features = ["functions", "unlock_notify"]
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -78,11 +78,6 @@
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "cc"
-version = "1.0.52"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
 name = "cfg-if"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -207,7 +202,6 @@
 version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cc 1.0.52 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "vcpkg 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -489,7 +483,6 @@
 "checksum blake2b_simd 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "d8fb2d74254a3a0b5cac33ac9f8ed0e44aa50378d9dbb2e5d83bd21ed1dc2c8a"
 "checksum bstr 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)" = "2889e6d50f394968c8bf4240dc3f2a7eb4680844d27308f798229ac9d4725f41"
 "checksum byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
-"checksum cc 1.0.52 (registry+https://github.com/rust-lang/crates.io-index)" = "c3d87b23d6a92cd03af510a5ade527033f6aa6fa92161e2d5863a907d4c5e31d"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
 "checksum constant_time_eq 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"