Let 'make' process all code coverage, even if errors occur.
Add support for running test drivers inside Valgrind.

This patch adds a '--valgrind' command line option to run_unit_tests.py. The option
accepts an argument which is a filename *pattern*. When this option is supplied,
each test case will be executed inside a Valgrind wrapper with the leak-check tool
enabled, and Valgrind's output will be directed (in XML format) to a file specified
by that pattern. The pattern will undergo string substitution with a single parameter,
which will be the test case number that is being executed (so the pattern should use
a "%d"-style format string to format it).
Correct some misspelled function names.
Add a 'Profile' configuration and code coverage tools.

This patch adds a 'Profile' configuration to common.gypi, and when the build
is done using GCC, adds specific compiler and linker flags to cause the library
and test drivers to be instrumented for profiling (and code coverage). In addition
it adds the 'tools/bsl_coverage' script which constructs a Makefile that uses 'lcov'
to gather and aggregate code coverage information, and it adds the 'lcov_cobertura'
tool which converts the lcov-style output into Cobertura-style output.
Revert "Disable profile/code coverage until tools are merged."

This reverts commit 25d61940a3a8bd8d1fae085081ae1c15aa96fa33.
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Import internal commit b6656a5e7b230abccc26be3153233f951daf4b32 : [APPROVAL] pending/master/bsl-stringbuf-readeof-drqs38933184 to master
Import internal commit b8cb1d6fe185bfc334e8a76cdac71e48b6c1d1d4 : [APPROVAL] pending/master/unordered_testing_revised to master
Import internal commit 0576197f8d36451c7e0041e013edad9cc941a15f : [APPROVAL] pending/master/gcc-4.7.0-cpp11-fixes-drqs31611140 to master
Import internal commit fd4898e249f741d0395efdc89dffe096a68cd2d2 : [APPROVAL] pending/master/type-traits-doc to master
Import internal commit dbcd057ffdaefb7372f07baeb0aeac5290d14aa9 : [APPROVAL] pending/master/eliminate_invented_legacy_in_bsls_drqs39194279 to master
Import internal commit d3523c85b82f06d29cf6654ce33f08fc8765d164 : [APPROVAL] pending/master/clean_up_bslmf_for_windows_drqs39269611 to master
Import internal commit ceaf74946686b4429e770cbe4e9fd4771965147a : [APPROVAL] pending/master/bsls-atomics-slow-tests-drqs39101345 to master