Support increased verbosity for debugging curl

[LucidOne]

This resolves my issues with #8, please let me know if it needs to be rebased.

$ src/metar -vv -d kiadRetrieving URL https://tgftp.nws.noaa.gov/data/observations/metar/stations/KIAD.TXT* Trying 140.90.101.79...* TCP_NODELAY set* Connected to tgftp.nws.noaa.gov (140.90.101.79) port 443 (#0)* ALPN, offering http/1.1* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH* successfully set certificate verify locations:* CAfile: /etc/ssl/certs/ca-certificates.crt CApath: /etc/ssl/certs* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384* ALPN, server accepted to use http/1.1* Server certificate:* subject: OU=Domain Control Validated; CN=dev.ncep.noaa.gov* start date: Feb 8 14:24:24 2019 GMT* expire date: Jan 27 15:34:06 2020 GMT* subjectAltName: host "tgftp.nws.noaa.gov" matched cert's "tgftp.nws.noaa.gov"* issuer: C=US; ST=Arizona; L=Scottsdale; O=GoDaddy.com, Inc.; OU=http://certs.godaddy.com/repository/; CN=Go Daddy Secure Certificate Authority - G2* SSL certificate verify ok.
> GET /data/observations/metar/stations/KIAD.TXT HTTP/1.1Host: tgftp.nws.noaa.govAccept: */*< HTTP/1.1 200 OK< Date: Wed, 13 Feb 2019 05:22:27 GMT< Server: Apache< X-Frame-Options: SAMEORIGIN< X-Content-Type-Options: nosniff< X-XSS-Protection: 1; mode=block< Last-Modified: Wed, 13 Feb 2019 04:54:17 GMT< Accept-Ranges: bytes< Content-Length: 156< Vary: Accept-Encoding< Content-Type: text/plain; charset=UTF-8< Strict-Transport-Security: max-age=31536000; includeSubdomains; preload< * Curl_http_done: called premature == 0* Connection #0 to host tgftp.nws.noaa.gov left intactKIAD 130452Z 26004KT 1SM R01R/P6000FT BR OVC004 02/01 A2966 RMK AO2 SFC VIS 4 RAE0354B08E23UPB0354E0355 SLP046 P0000 T00170011 400330000 $Parsing token `KIAD' Found station KIADParsing token `130452Z' Found Day/Time 13/452Parsing token `26004KT' Found Winddir/str/gust/unit 260/4/4/KTParsing token `1SM' Visibility range/unit 1/SMParsing token `R01R/P6000FT' Unmatched token = R01R/P6000FTParsing token `BR' Phenomena MistParsing token `OVC004' Cloud cover/alt OVC/400Parsing token `02/01' Temp/dewpoint 2/1Parsing token `A2966' Pressure/unit 2966/"HgParsing token `RMK' Unmatched token = RMKParsing token `AO2' Unmatched token = AO2Parsing token `SFC' Unmatched token = SFCParsing token `VIS' Unmatched token = VISParsing token `4' Unmatched token = 4Parsing token `RAE0354B08E23UPB0354E0355' Unmatched token = RAE0354B08E23UPB0354E0355Parsing token `SLP046' Unmatched token = SLP046Parsing token `P0000' Unmatched token = P0000Parsing token `T00170011' Unmatched token = T00170011Parsing token `400330000' Unmatched token = 400330000Parsing token `$' Unmatched token = $Station : KIADDay : 13Time : 04:52 UTCWind direction: 260 (W)Wind speed : 4 KTWind gust : 4 KTVisibility : 1 SMTemperature : 2 CDewpoint : 1 CPressure : 29.66 "HgClouds : OVC at 400 ftPhenomena : Mist