Fix a few typos in man page

bwa.1

@@ -302,7 +302,7 @@ Output all found alignments for single-end or unpaired paired-end reads. These
 alignments will be flagged as secondary alignments.
 .TP
 .B -C
-Append append FASTA/Q comment to SAM output. This option can be used to
+Append FASTA/Q comment to SAM output. This option can be used to
 transfer read meta information (e.g. barcode) to the SAM output. Note that the
 FASTA/Q comment (the string after a space in the header line) must conform the SAM
 spec (e.g. BC:Z:CGTAC). Malformated comments lead to incorrect SAM output.
@@ -316,7 +316,7 @@ supplementary alignments.
 Mark shorter split hits as secondary (for Picard compatibility).
 .TP
 .BI -v \ INT
-Control the verbose level of the output. This option has not been fully
+Control the verbosity level of the output. This option has not been fully
 supported throughout BWA. Ideally, a value 0 for disabling all the output to
 stderr; 1 for outputting errors only; 2 for warnings and errors; 3 for
 all normal messages; 4 or higher for debugging. When this option takes value