Add //third_party/sqlite to dirs_to_snapshot, remove net_sql.patch

third_party/sqlite/src/autoconf/README

+
+This package contains:
+
+ * the SQLite library amalgamation (single file) source code distribution,
+ * the shell.c file used to build the sqlite3 shell too, and
+ * the sqlite3.h and sqlite3ext.h header files required to link programs
+   and sqlite extensions against the installed libary.
+ * autoconf/automake installation infrastucture.
+
+The generic installation instructions for autoconf/automake are found
+in the INSTALL file.
+
+The following SQLite specific boolean options are supported:
+
+  --enable-readline           use readline in shell tool   [default=yes]
+  --enable-threadsafe         build a thread-safe library  [default=yes]
+  --enable-dynamic-extensions support loadable extensions  [default=yes]
+
+The default value for the CFLAGS variable (options passed to the C 
+compiler) includes debugging symbols in the build, resulting in larger
+binaries than are necessary. Override it on the configure command
+line like this:
+
+  $ CFLAGS="-Os" ./configure
+
+to produce a smaller installation footprint.
+
+Other SQLite compilation parameters can also be set using CFLAGS. For
+example:
+
+  $ CFLAGS="-Os -DSQLITE_OMIT_TRIGGERS" ./configure
+