Greater standardization of sizing terminology

BS3 commit 23ef8c0c209844dd8b92d2a5ac82daffa7bd2914
Greater standardization of sizing terminology. rm stray space in components.html. add .btn-xs to .btn-group example. trivial docs grammar improvements. adjust description & give source for nested `.btn-group`s example. components.html: rm disconnected sentence fragment

BS3 commits 23ef8c0c209844dd8b92d2a5ac82daffa7bd2914,
7a04e95b719c118ef531511300617f3edd361b08,
b9c572184f18a5c228dedd41e3b93b94c8d71b7b,
b6390d298aa71e6dccb10e539097fbc7aaa45b8a,
509ffe110ecf78998a32e5603abedc79d526235d,
a84e07b27220eddb075d4df65fe24d26c722df7a
Greater standardization of sizing terminology. update line-height. add missing ref to .btn-xs in button sizes docs

BS3 commits 23ef8c0c209844dd8b92d2a5ac82daffa7bd2914,
cabcd36019cb7000c537bcd8292d4905239685f7
Greater standardization of sizing terminology. JS docs: capitalize Bootstrap. streamline $().dropdown('toggle') description. trivial docs grammar improvements

BS3 commits 23ef8c0c209844dd8b92d2a5ac82daffa7bd2914,
eed4844fd2d12255c0e48acbf2b7132cefd6aaff,
899c147cd561a4fd8757cb76124036e5a73c5c92,
b6390d298aa71e6dccb10e539097fbc7aaa45b8a
Greater standardization of sizing terminology

BS3 commit 23ef8c0c209844dd8b92d2a5ac82daffa7bd2914