* `git ls-files -- '*.go' | xargs gofmt -s -w`

* driver: unexport InternalOptions

This was an exported method that returned an internal type, so it's
unlikely that anyone depends on its presence.

* internal/binutils: remove newline in error string

golint reported: error strings should not be capitalized or end with
punctuation or a newline

* internal/driver: s/buildId/buildID/ per golint

* internal/elfexec: remove punctuation in error string

golint reported: error strings should not be capitalized or end with
punctuation or a newline

* internal/graph: correct comment

Found with golint.

* internal/graph: add method comment

golint reported: exported method Edge.WeightValue should have comment
or be unexported

* internal/report: remove newline in error string

golint reported: error strings should not be capitalized or end with
punctuation or a newline

* *: remove unused code

Found with honnef.co/go/tools/cmd/unused:

	internal/binutils/disasm_test.go:137:8: const objdump is unused (U1000)
	internal/driver/driver_test.go:353:6: type testProfile is unused (U1000)
	internal/graph/graph.go:838:6: func countEdges is unused (U1000)
	profile/proto.go:148:6: func encodeStringOpt is unused (U1000)

* *: simply code

Found with honnef.co/go/tools/cmd/gosimple:

	internal/driver/commands.go:471:24: should omit comparison to bool constant, can be simplified to !b (S1002)
	internal/driver/driver.go:163:5: should omit comparison to bool constant, can be simplified to !trim (S1002)
	internal/driver/driver.go:168:5: should omit comparison to bool constant, can be simplified to !focus (S1002)
	internal/driver/driver.go:172:5: should omit comparison to bool constant, can be simplified to !tagfocus (S1002)
	internal/driver/driver.go:176:5: should omit comparison to bool constant, can be simplified to !hide (S1002)
	internal/graph/dotgraph.go:213:34: should use make(map[string][]*Tag) instead (S1019)
	internal/report/report.go:1061:3: should replace loop with label = append(label, rpt.options.ProfileLabels...) (S1011)
	profile/proto.go:157:5: should omit comparison to bool constant, can be simplified to !x (S1002)

* *: correct mistakes

Found with honnef.co/go/tools/cmd/staticcheck:

	driver/driver.go:280:20: infinite recursive call (SA5007)
	internal/driver/driver_focus.go:54:11: this value of err is never used (SA4006)
	profile/proto.go:74:32: x | 0 always equals x (SA4016)

* Add linters to .travis.yml

Mainly use imported structs by field and update a mismatch printf
string on a test error message.

Even after local symbolization completes successfully we should
call remote symbolization in case there are some mapping that couldn't
be symbolized otherwise.

Add some tests to ensure both local and symbolz symbolization are called.

When reconciling samples, cleanup file paths to allow functions to be
combined if their source filenames match after cleanup (eg "src.cpp" and
"./src.cpp").

Also clean up existing uses of filepath to avoid passing empty strings
to it: filepath.Base("") returns "."

Also update the build instructions to use go get